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Innovation Center of

Faculty of Mechanical

Engineering

„International Conference of Experimental and

Numerical Investigations and New Technologies“

MINISTRY OF EDUCATION, SCIENCE AND TECHNICAL DEVELOPMENT

OF THE REPUBLIC OF SERBIA

Programme

The Book of Abstracts

Faculty of Mechanical

Engineering, University

of Belgrade

Center for Business

Trainings



Sponsored by:


OF THE REPUBLIC OF SERBIA

Programme

and


04-06 July 2018

Zlatibor, Serbia

Center for Business

Trainings





„International Conference of Experimental and Numerical

Investigations and New Technologies“

CNN TECH 2018 04-06 July 2018

Hotel Mona, Miladina Pecinara 26, Zlatibor, Serbia

http://cnntechno.com

Programme

and


Organised by:

Innovation Center of Faculty of Mechanical Engineering

Faculty of Mechanical Engineering, University of Belgrade

Center for Business Trainings

Sponsored by:

Ministry of Education, Science and Technical development of the Republic of Serbia

Title: International Conference of Experimental and Numerical Investigations and New Technologies – CNN TECH 2018

PROGRAMME AND THE BOOK OF ABSTRACTS

Publisher: Innovation Center of Faculty of Mechanical Engineering Kraljice Marije 16, 11120 Belgrade 35 tel: (+381 11) 3302-346, fax 3370364 e-mail: [email protected] web site: http://cnntechno.com, http://www.inovacionicentar.rs

Editors: Dr Nenad Mitrovic, Assistant Professor Dr Milos Milosevic, Senior Scientific Researcher Dr Goran Mladenovic, Assistant Professor

Technical editor Dr Goran Mladenovic, Assistant Professor

Cover page: Dr Goran Mladenovic, Assistant Professor

Printed in: Innovation Center of Faculty of Mechanical Engineering Kraljice Marije 16 11120 Belgrade 35 tel: (+381 11) 3302-346

Circulation: 70 copies. The end of printing: July 2018.

ISBN: 978-86-7083-979-3

Copyright© 2018 International Conference of Experimental and Numerical Investigations and New Technologies – CNN TECH 2018

“International Conference of

Experimental and Numerical

Investigations and New Technologies”

CNN TECH 2018

SCIENTIFIC COMMITTEE:

Miloš Milošević, Serbia (chairman) Nenad Mitrović, Serbia (co-chairman) Aleksandar Sedmak, Serbia Hloch Sergej, Slovakia Dražan Kozak, Croatia Nenad Gubeljak Slovenia Monka Peter, Slovakia Snežana Kirin, Serbia Samardžić Ivan, Croatia Martina Balać, Serbia Mládková Ludmila, Czech Republic Johanyák Zsolt Csaba, Hungary Igor Svetel, Serbia Aleksandra Mitrović, Serbia

Valentin Birdeanu, Romania Danilo Nikolić, Montenegro Goran Mladenović, Serbia Bajić Darko, Montenegro Tasko Maneski, Srbija Luis Reis, Portugal Žarko Mišković, Serbia Tozan Hakan, Turkey Nikola Momčilović, Serbia Traussnigg Udo, Austria Zoran Janjus, Bosnia and Herzegovina Gordana Bakić, Serbia Katarina Čolić, Serbia Jovan Tanasković, Serbia

ORGANIZING COMMITTEE:

Nenad Mitrović (chairman) Miloš Milošević (co-chairman) Aleksandar Sedmak Martina Balać Igor Svetel Goran Mladenović Aleksandra Mitrović Aleksandra Dragicević Žarko Mišković Katarina Čolić Milan Travica

ACKNOWLEDGEMENT

The organizing committee of the 2nd International Conference of Experimental and Numerical Investigations and New Technologies – CNN TECH 2018 wishes to sincerely thank all the institutions and individuals who by means of personal engagement and constructive action helped organizing this conference.

We particularly wish to thank our sponsor, The Ministry of Education, Science and Technological development, Government of the Republic of Serbia.

PREFACE

Dear Friends and Colleagues, Welcome to CNN Tech 2018 Conference and the

fabulous mountain of Zlatibor!

With 40 papers (17 by international authors) and contributions by authors from 11

different countries, International Conference of Experimental and Numerical

Investigations and New Technologies CNN Tech 2018 successfully sets the high

level for the future conferences. Participation of a large number of domestic and

international authors, as well as the diversity of topics, justifies our efforts to organize

this conference and contribute to exchange of knowledge, research results and

experience of industry experts, research institutions and faculties which all share a

common interest in the field in experimental and numerical investigations.

This year CNN Tech 2018 focuses on the following topics:

− Mechanical Engineering,

− Materials Science,

− Chemical and Process Engineering,

− Experimental Techniques,

− Numerical Methods,

− New Technologies.

Apart from a plenty of interesting lectures, the participants will have a chance to

lighten up and communicate in friendly and relaxed settings.

Organizing committee of CNN Tech 2018 would like to express gratitude to Ministry

of Education, Science and Technological development for financial support of the

Conference.

On behalf of the Innovation center of Faculty of Mechanical Engineering, Faculty of

Mechanical Engineering and Center for Business Trainings, we wish this to be

splendid CNN Tech conference filled with many memorable moments.

PROGRAMME AND ORGANIZING COMMITTEE

CONTENTS

PROGRAMME ................................................................................................................................. i

ABSTRACTS .................................................................................................................................. 1

Mechanical Engineering ............................................................................................................... 2

Emina S Dzindo

J-INTEGRAL IN ELASTO-PLASTIC FRACTURE ................................................................... 3

Natasa A. Kablar HEAT AND ELECTRICITY PRODUCTION FROM BIOMASS................................................. 4

Jasmina Lozanovic Sajic,Maja Djurovic-Petrovic, Sasa Petrovic AUTOMATIC DETECTION OF CARBON MONOXIDE (CO) IN THE GARAGES OF

RESIDENTIAL AND COMMERCIAL BUILDINGS ................................................................... 5

Jovan D. Tanaskovic, Martina M. Balac

STATIC STRENGTH ANALYSES OF THE STEEL STRUCTURE OF BIOMASS

RESERVOIR UNDER HYDROSTATIC PRESSURE ............................................................... 6

Stefan G. Culafic

NUMERICAL AND EXPERIMENTAL ANALYSIS OF STRENGTH OF STRUCTURAL

ELEMENTS IN HYDRO - POWER PLANTS ........................................................................... 7

Mirko Dobrnjac, Milos Markovic

THE SOLAR MEASUREMENT STATION FOR EXAMINATION OF THE THERMAL

RECEIVER FOR SOLAR ENERGY ......................................................................................... 8

Milan Travica, Nenad Mitrovic, Aleksandar Petrovic

COMPARISON BETWEEN DIFFERENT CALCULATION PROCEDURES OF LOADS

CAUSED BY TEMPERATURE DILATATION IN PIPELINES ................................................. 9

Snezana Kirin

INNOVATION MANAGEMENT- LEAN ENTERPRISE .......................................................... 10

Darko Jocic, Velimir Cirovic, Dragan Aleksendric

IDENTIFICATION AND RECOGNITION OF VEHICLE ENVIRONMENT USING

ARTIFICIAL NEURAL NETWORKS...................................................................................... 11

Boris Kosic, Misa Stojicevic, Zorana Jeli, Branislav Pokonstantinovic, Aleksandra

Dragicevic

DESIGN STUDY OF THE DIFERENT METAMATERIAL SHAPES ....................................... 12

Aleksandra Dragicevic, Boris Kosic, Zorana Jeli

THE NEW METHOD FOR REMOVING HIGHLY CORRELATED VARIABLES FROM

DATASETS ........................................................................................................................... 13

Materials Science ........................................................................................................................ 14

Ivan Tanasic, Ljiljana Tihacek Sojic

ANALYSING SAMPLES AND SPECIMENS IN DENTAL BIOMECHANICS ....................... 15

Aleksandra D. Mitrovic, AleksandraLj.Dragicevic, Dejana P. Popovic, Manuel Conte,

Dragomir M. Stamenkovic

TGA AND DTA ANALYSIS OF SOFT CONTACT LENSES BASED ON POLY

(HYDROXYETHYL METHACRYLATE) AND FULLERENES ............................................ 16

Reljic M. Mirjana, Stojiljkovic T. Stanisa, Stepanovic M. Jovan, Lazic B. Branislava, Milena

S. Stojiljkovic

EXPLORATION OF THE CHANGES OF PROPERTIES OF WATER VAPOUR

RESISTANCE OF Co/PES FABRICS DURING MAINTENANCE ......................................... 17

Aleksandra Mitrovic, Nenad Mitrovic, Dejana Popovic, Milos Milosevic, Vladimir Miljkovic

EXPERIMENTAL STUDY OF TEXTILE DEFORMATION USING 3D DIGITAL IMAGE

CORRELATION METHOD .................................................................................................... 18

T. Jovanovic, Dj. Koruga, A. Mitrovic, D. Stamenkovic, M. Tomic, J. Sakota-Rosic and M.

Cvetkovic

IR SPECTROSCOPYOF THE HIGHER FULLERENE C84-D2:22 FOR ITS

QUALITATIVE AND QUANTITATIVE DETERMINATION ..................................................... 19

Chemical and Process Engineering .......................................................................................... 20

Ivan M. Buzurovic, Dragutin Lj. Debeljkovic, Darko M. Radojevic, Goran V. Simeunovic

ASYMPTOTIC STABILITY OF SINGULAR TIME DELAY SYSTEMS: LYAPUNOV’S

APPROACH BASED ON JENSEN’S AND COPPEL’S INEQUALITY ................................. 21

Ivan M. Buzurovic, Dragutin Lj. Debeljkovic, Aleksandra M. Jovanovic, Goran V.

Simeunovic

LYAPUNOV STABILITY OF DISCRETE DESCRIPTOR DELAYED SYSTEMS:

APPROACH BASED ON CONVOLUTION AND JENSEN’S INEQUALITY .......................... 22

Milena S. Stojiljkovic, StanisaT. Stojiljkovic, Bratislav Z. Todorovic, Mirjana M. Reljic

PHASE CHANGE BIODEGRADABLE MATERIALS BASED ON ORGANICALLY

MODIFIED CLAY, PARAFFIN AND WASTE FATTY ACID (MONG) .................................... 23

Sanja Dobrnjac, Mirko Dobrnjac, Jelena Penavin Skundric, Ljubica Vasiljevic, Stevan

Blagojevic, Zvjezdana Sandic

POSSIBILITY FOR REMOVING PRODUCTS OF THERMAL DEGRADATION OF

EDIBLE OIL BY NATURAL ALUMINOSILICATES ............................................................... 24

Nenad Mitrovic

APPLICATION OF 3D DIGITAL IMAGE CORRELATION METHOD IN PROCESS

ENGINEERING ...................................................................................................................... 25

Nebojsa Manic, Bojan Jankovic, Dragoslava Stojiljkovic, Vladimir Jovanovic, Martina

Balac

TGA-DSC-MS ANALYSIS OF PYROLYSIS PROCESS OF VARIOUS BIOMASSES

WITH ISOCONVERSIONAL (MODEL-FREE) KINETICS ...................................................... 26

Marta Trninic, Dusan Todorovic, Aleksandar Jovovic, Dragoslava Stojiljkovic, Øyvind

Skreiberg, Liang Wang, Nebojsa Manic MATHEMATICAL MODELLING AND PERFORMANCE ANALYSIS OF A SMALL-

SCALE COMBINED HEAT AND POWER SYSTEM BASED ON BIOMASS WASTE

DOWNDRAFT GASIFICATION ............................................................................................. 27

Experimental Techniques ........................................................................................................... 28

Vuk Adžic, Mustafa Makhzoum, Aleksandar Milivojevic and Miroljub Adžic

RESEARCH OF LEAN PREMIXED COMBUSTOR BY CHEMILUMINESCENCE

TOMOGRAPHY ..................................................................................................................... 29

Aleksandra Mitrovic, Nenad Mitrovic, Dejana Popovic, Milos Milosevic, Dusan Antonovic

BIOMECHANICAL BEHAVIOR OF RESIN BASED CEMENTMAXCEM ELITE ................... 30

Jovan D. Tanaskovic, Aleksandra D. Mitrovic, Francis J. Franklin, Dragan D. Milkovic

IMPACT OF DENSITY OF POLYURETHANE FOAM ON ABSORPTION POWER OF

ENERGY ABSORBER .......................................................................................................... 31

Martina Balac

STRUCTURAL OPTIMIZATION OF PRESSURE VESSELS USING FEA ............................ 32

Vera Cerovic, Dragan Milkovic, Aleksandar Grbovic, Sasa Radulovic, Jovan Tanaskovic

EXPERIMENTAL MEASUREMENTS OF THE STRESSES IN THE LOWER LINK OF

THE THREE-POINT HITCH MECHANISM ............................................................................ 33

Martina Balac, Aleksandar Grbovic

MULTIPARAMETER STRUCTURAL OPTIMIZATION OF PRESSURE VESSEL WITH

TWO NOZZLES ..................................................................................................................... 34

Milos Milosevic, Srdan Postic, Nenad Mitrovic, Aleksa Milovanovic, Milan Travica, Sergej

Hloch, Zorana Golubovic

STRAIN MEASUREMENT SETUP OF COMPRESSIVELY LOADED MANDIBLE

MODEL WITH TEETH AND COMPENSATIONS .................................................................. 35

Numerical Methods ..................................................................................................................... 36

Maksimovic S. Katarina, Vasovic V. Ivana, Maksimovic S. Mirko, Dragi Stamenkovic

DETERMINATION OF FRACTURE MECHANICS PARAMETERS OF STRUCTURAL

COMPONENTS UNDER THERMOMECHANICAL LOADS .................................................. 37

Nikola Mirkov, Nenad Vidanovic, Gordana Kastratovic

AN OPEN SOURCE SOFTWARE LIBRARY FOR COMPUTATIONAL CONTINUUM

MECHANICS ......................................................................................................................... 38

Zarko Miskovic, Radivoje Mitrovic, Milan Tasic, Marko Tasic and Ján Danko

APPLICATION OF FINITE ELEMENT METHOD FOR DETERMINATION OF AXIAL

LOAD ON CONVEYOR WING ROLLERS............................................................................. 39

Miodrag Milcic, Tomaz Vuherer, Igor Radisavljevic, Dragan Milcic

EXPERIMENTAL INVESTIGATION OF MECHANICAL BEHAVIOUR OF AL 2024

ALLOY WELDED BY FRICTION STIR WELDING ................................................................ 40

Natasa A. Kablar

COMPUTATIONAL STUDY OF WNT SIGNALING PATHWAY IN ALZHEIMER

DISEASE ............................................................................................................................... 41

Katarina Colic, Aleksandar Grbovic, Aleksandar Sedmak, Kaled Legweel, Uros Tatic

NUMERICAL METHODS IN ASESSMENT OF HIP IMPLANT DESIGN AND INTEGRITY ... 42

New Technologies ...................................................................................................................... 43

Ivana Vlajic Naumovska, Zeljko Despotovic, Borko Cupic

USAGE OF DC-DC CONVERTERS ...................................................................................... 44

Natasa A. Kablar

WIRELESS ROBOT ARM CONTROL BASED ON ARDUINO MICROCONTROLLER ......... 45

Aleksa Milovanovic, Milos Milosevic, Goran Mladenovic, Blaz Likozar, Katarina Colic,

Nenad Mitrovic

ACCURACY OF POLYMER ELECTROLYTE MEMBRANE (PEM) FUEL CELL

REFORMER PROTOTYPES USING FDM AND SLA 3D PRINTING TECHNOLOGY IN

COMPARISON WITH DIGITAL CAD MODEL ....................................................................... 46

Goran M. Mladenovic, Marko J. Milovanovic, Ljubodrag M. Tanovic, Tim J. Jones, Milos

D. Pjevic

MANUFACTURING AND GEOMETRY MEASUREMENT OF PARTS WITH FREE FORM

SURFACES ........................................................................................................................... 47

i

PROGRAMME

Tuesday, July 03, 2018

17:00 to 18:00 Registration

18:00 to 21:00 Welcome dinner

Wednesday, July 04, 2018

09:00 to 10:00 Registration

10:00 to 10:30 Opening Ceremony

10:30 to 11:30

KEYNOTE LECTURES Nikola Mirkov - AN OPEN SOURCE SOFTWARE LIBRARY FOR COMPUTATIONAL CONTINUUM MECHANICS Martina Balac- STRUCTURAL OPTIMIZATION OF PRESSURE VESSELS USING FEA

11:30 to 12:00 Coffee break

12:00 to 14:00

SESSION I (Oral presentations)

1. Invited lecture –Nenad Mitrovic APPLICATION OF 3D DIGITAL IMAGE CORRELATION METHOD IN PROCESS ENGINEERING

2. Aleksandra Mitrovic, Nenad Mitrovic, Dejana Popovic, Milos Milosevic, Dusan Antonovic BIOMECHANICAL BEHAVIOR OF RESIN BASED CEMENT MAXCEM ELITE

3. Radivoje Mitrovic, Milan Tasic, Zarko Miskovic, Marko Tasic APPLICATION OF FINITE ELEMENT METHOD FOR DETERMINATION OF AXIAL LOAD ON CONVEYOR WING ROLLERS

4. Aleksa Milovanovic, Milos Milosevic, Goran Mladenovic, Blaz Likozar, Katarina Colic, Nenad Mitrovic ACCURACY OF POLYMER ELECTROLYTE MEMBRANE (PEM) FUEL CELL REFORMER PROTOTYPES USING FDM AND SLA 3D PRINTING TECHNOLOGY IN COMPARISON WITH DIGITAL CAD MODEL

5. Jasmina Lozanovic Sajic, Maja Djurovic-Petrovic, Sasa Petrovic AUTOMATIC DETECTION OF CARBON MONOXIDE (CO) IN THE GARAGES OF RESIDENTIAL AND COMMERCIAL BUILDINGS

6. Aleksandra Dragicevic, Boris Kosic, Zorana Jeli THE NEW METHOD FOR REMOVING HIGHLY CORRELATED VARIABLES FROM DATASETS

14:00 to 15:00 Refreshment

15:00 to 17:00 SESSION II (Poster presentations)

17:00 to 19:00 Free time

19:00 to 21:00 Gala dinner

ii

Thursday, July 05, 2018

10:00 to 11:30

SESSION III (Oral presentations)

1. Invited lecture – Sanja Dobrnjac, Mirko Dobrnjac, Jelena Penavin Skundric, Ljubica Vasiljevic, Stevan Blagojevic, Zvjezdana Sandic POSSIBILITY FOR REMOVING PRODUCTS OF THERMAL DEGRADATION OF EDIBLE OIL BY NATURAL ALUMINOSILICATES

2. Invited lecture – Mirko Dobrnjac, Milos Markovic THE SOLAR MEASUREMENT STATION FOR EXAMINATION OF THE THERMAL RECEIVER FOR SOLAR ENERGY

3. Darko Jocic, Velimir Cirovic, Dragan Aleksendric IDENTIFICATION AND RECOGNITION OF VEHICLE ENVIRONMENT USING ARTIFICIAL NEURAL NETWORKS

4. Natasa Kablar COMPUTATIONAL STUDY OF WNT SIGNALING PATHWAY IN ALZHEIMER DISEASE

5. Goran Mladenovic, Marko Milovanovic, Ljubodrag Tanovic, Tim Jones, Milos Pjevic MANUFACTURING AND GEOMETRY MEASUREMENT OF PARTS WITH FREE FORM SURFACES


12:00 to 14:00 WORKSHOP (INTELLECTUAL PROPERTY)

14:00 to 15:00 Refreshment

15:00 to 16:30

SESSION IV (Oral presentations)

1. Invited lecture – Snezana Kirin INNOVATION MANAGEMENT - LEAN ENTERPRISE

2. Invited lecture – Stefan Culafic NUMERICAL AND EXPERIMENTAL ANALYSIS OF STRENGTH OF STRUCTURAL ELEMENTS IN HYDRO - POWER PLANTS

3. Marta Trninic, DuSan Todorovic, Aleksandar Jovovic, Dragoslava Stojiljkovic, Øyvind Skreiberg, Liang Wang, NebojSa Manic MATHEMATICAL MODELLING AND PERFORMANCE ANALYSIS OF A SMALL-SCALE COMBINED HEAT AND POWER SYSTEM BASED ON BIOMASS WASTE DOWNDRAFT GASIFICATION

4. Nebojsa Manic, Bojan Jankovic, Dragoslava Stojiljkovic, Vladimir Jovanovic, Martina Balac TGA-DSC-MS ANALYSIS OF PYROLYSIS PROCESS OF VARIOUS BIOMASSES WITH ISOCONVERSIONAL (MODEL-FREE) KINETICS

5. Vera Cerovic, Dragan Milkovic, Aleksandar Grbovic, Sasa Radulovic, Jovan Tanaskovic EXPERIMENTAL MEASUREMENTS OF THE STRESSES IN THE LOWER LINK OF THE THREE-POINT HITCH MECHANISM

6. Katarina Colic, Aleksandar Grbovic, Aleksandar Sedmak, Kaled Legweel, UroS Tatic NUMERICAL METHODS IN ASESSMENT OF HIP IMPLANT DESIGN AND INTEGRITY


17:00 to 18:00 WORKSHOP(EU PROJECTS – NEW PROJECT IDEAS)

18:00 to 21:00 Dinner

iii

Friday, July 06, 2018

10:00 to 10:30 Closing ceremony

From 10:30 Zlatibor excursion

1

ABSTRACTS

2

Mechanical Engineering

CNN TECH 2018 - The Book of Abstracts

J-INTEGRAL IN ELASTO

1Innovation Center of Faculty of Mechanical Engineering, Kraljice

*Corresponding author

Abstract

The elastic-plastic fracture mechanics parameters evaluated in this paper, i.e. Jsensitive to calculation technique used. In other words, differences in their values, obtained by changing finite element techniques such as significant. Application of the finite element method to the elasticwith ESIS recommendations. Thus, the quadrangle eightwhile the crack tip singularity was modelledand mid-side nodes and mid-side nodes. For the static load case, one should differentiate between the material behaviour, which is described as linearly elastic, and the material cannot be neglected. In the former case the linear elastic fracture mechanics (LEFM) applies, while in the latter case, depending on the form of the material plastic flow, mechanics were used. The J-integral is path independent, as shown by its evaluation along six different paths, which is another proof of its correct evaluation. The basic aim of this paper is to contribute to the aintegrity of a cracked combustion chamber, i.e. cylindrical pressure vessel. Toward this end elasticfracture mechanics parameters were evaluated, which could serve as crack driving forces for any cracked structure. As the relevant parameters, the Jchosen and evaluated by the elasticsurface crack was represented as twoof edge cracked plate loaded by remote tensile stress.

Keywords

Finite elements, pressure vessel, elastic


Numerical Investigations and New

Zlatibor, July 0


INTEGRAL IN ELASTO-PLASTIC FRACTUREEmina S Dzindo1*

Innovation Center of Faculty of Mechanical Engineering, Kraljice Marije 16, 11120 Belgrade 35

Republic of Serbia

Corresponding author e-mail: [email protected]

plastic fracture mechanics parameters evaluated in this paper, i.e. J-integral and CTOD, are not sensitive to calculation technique used. In other words, differences in their values, obtained by changing finite element techniques such as modelling the material behaviour and prescribing the loading, are not

Application of the finite element method to the elastic-plastic fracture mechanics problem was in accordance , the quadrangle eight-nodded isoperimetric finite

modelled by triangular elements with three independent nodes at crack tip side nodes. For the static load case, one should differentiate between the

ch is described as linearly elastic, and the material behaviourcannot be neglected. In the former case the linear elastic fracture mechanics (LEFM) applies, while in the latter case, depending on the form of the material plastic flow, various forms of elastic

integral is path independent, as shown by its evaluation along six different paths, which is another proof of its correct evaluation. The basic aim of this paper is to contribute to the aintegrity of a cracked combustion chamber, i.e. cylindrical pressure vessel. Toward this end elasticfracture mechanics parameters were evaluated, which could serve as crack driving forces for any cracked

relevant parameters, the J-integral and crack tip opening displacement (CTOD) were chosen and evaluated by the elastic-plastic finite element method. The combustion chamber with an axial surface crack was represented as two-dimensional plane strain elastic-plastic finite element model, in a form of edge cracked plate loaded by remote tensile stress.

inite elements, pressure vessel, elastic-plastic fracture, J-integral, CTOD

3


estigations and New Technologies“

Zlatibor, July 04-06, 2018


IC FRACTURE

Marije 16, 11120 Belgrade 35

integral and CTOD, are not sensitive to calculation technique used. In other words, differences in their values, obtained by changing

and prescribing the loading, are not

plastic fracture mechanics problem was in accordance nodded isoperimetric finite elements were used,

by triangular elements with three independent nodes at crack tip side nodes. For the static load case, one should differentiate between the

behaviour when the plasticity cannot be neglected. In the former case the linear elastic fracture mechanics (LEFM) applies, while in the

various forms of elastic-plastic fracture

integral is path independent, as shown by its evaluation along six different paths, which is another proof of its correct evaluation. The basic aim of this paper is to contribute to the assessment of structural integrity of a cracked combustion chamber, i.e. cylindrical pressure vessel. Toward this end elastic-plastic fracture mechanics parameters were evaluated, which could serve as crack driving forces for any cracked

integral and crack tip opening displacement (CTOD) were plastic finite element method. The combustion chamber with an axial

plastic finite element model, in a form


HEAT AND ELECTRICITY

1

*Corresponding author e

Abstract

In this paper we explain basic principles of biomass energy transformation into heat and electricity. propose technical system that convertswarm the water or other fluid in order to produce heat, or which use steam turbine and generator of electrical energy in order to produce electricity. We give block diagram. Our aim is to develop small technical system that will serve as prototype. We are also interested in batteries development in order to store electricity, or to provide electrical energy directly to grid. This kind of tadditional way of providing electrical energy in homes. This is so additional form of electrical energy can be used any form geothermal, or electricity from generators, accumulators or batteries.

Keywords

Biomass energy, technical system prototype, electrical energy generation, green energy



Zlatibor, July 0


HEAT AND ELECTRICITY PRODUCTION FROM

BIOMASS Natasa A. Kablar1*

1Lola Institute, 11000 Belgrade, Serbia


In this paper we explain basic principles of biomass energy transformation into heat and electricity. system that converts biomass energy through process of combustion in furnace in order to

warm the water or other fluid in order to produce heat, or which use steam turbine and generator of electrical ity. We give block diagram. Our aim is to develop small technical system

that will serve as prototype. We are also interested in batteries development in order to store electricity, or to provide electrical energy directly to grid. This kind of technical system can be used as additional way of providing electrical energy in homes. This is so called hybrid energy concept,

form of electrical energy can be used any form of green energies - wind, solar, water, biomass or or electricity from generators, accumulators or batteries.

energy, technical system prototype, electrical energy generation, green energy

4





PRODUCTION FROM

[email protected]

In this paper we explain basic principles of biomass energy transformation into heat and electricity. We biomass energy through process of combustion in furnace in order to

warm the water or other fluid in order to produce heat, or which use steam turbine and generator of electrical ity. We give block diagram. Our aim is to develop small technical system

that will serve as prototype. We are also interested in batteries development in order to store generated echnical system can be used as hybrid energy concept, whereas

wind, solar, water, biomass or

energy, technical system prototype, electrical energy generation, green energy


AUTOMATIC DETECTION

IN THE GARAGES OF RE

COMMERCIAL BUILDINGJasmina Lozanovi

1University of Belgrade, Faculty of Mechanical Engineering, Department of Information Technologies, 11000

2PhD candidate on Mechanical Engineering Faculty University of Ni


Abstract

This paper presents the method of automatic detection of carbon monoxide (CO) concentration. The exhaust gases of the engine contain carbon monoxide toxic gas. Therefore, regulations stipulate that every closed garage must have an automatic detection system for carbon monoxide. It has no It is cytotoxic for living beings, as it belongs to the group of chemical (about 50 percent of poisoning in the world is from this gas).The exhaust gases of internal combustion engines are one of the biggest atmospheric pollutants with this gas, then exhaust gases that occur during the proand in the process of production in oil refineries and the chemical industry.The automatic detection system can detect at the same time and several different gases, with an adequate detector. Thanks to the new technology in the design of the central and gas sensors, the system has a high sensitivity and fast response. When the gas concentration reaches or exceeds the set alarm levels, the control panel immediately illuminates and activates the other immediately and sounds.

Keywords

Control system, Automatic detection system, carbon monoxide.

Acknowledgement

This work is a contribution to the Ministry of Education, Science and Technological Development, RepuSerbia funded project TR35013.



Zlatibor, July 0


AUTOMATIC DETECTION OF CARBON MONOXIDE (

IN THE GARAGES OF RESIDENTIAL AND

COMMERCIAL BUILDINGS Lozanovic Sajic1*, Maja Djurovic-Petrovic1, Sasa Petrovi

University of Belgrade, Faculty of Mechanical Engineering, Department of Information Technologies, 11000 Belgrade, Serbia

PhD candidate on Mechanical Engineering Faculty University of Nis, Serbia

*Corresponding author e-mail: [email protected]

This paper presents the method of automatic detection of carbon monoxide (CO) concentration. The exhaust on monoxide toxic gas. Therefore, regulations stipulate that every closed

garage must have an automatic detection system for carbon monoxide. It has no colourIt is cytotoxic for living beings, as it belongs to the group of chemical buffers and the biggest air pollutants (about 50 percent of poisoning in the world is from this gas). The exhaust gases of internal combustion engines are one of the biggest atmospheric pollutants with this gas, then exhaust gases that occur during the production of iron, coal combustion in thermal power plants and in the process of production in oil refineries and the chemical industry. The automatic detection system can detect at the same time and several different gases, with an adequate

to the new technology in the design of the central and gas sensors, the system has a high sensitivity and fast response. When the gas concentration reaches or exceeds the set alarm levels, the control panel immediately illuminates and activates the other outputs for the desired executive functions

Control system, Automatic detection system, carbon monoxide.

This work is a contribution to the Ministry of Education, Science and Technological Development, Repu

5





OF CARBON MONOXIDE (CO)

SIDENTIAL AND

a Petrovic2

University of Belgrade, Faculty of Mechanical Engineering, Department of Information Technologies, 11000

s, Serbia

This paper presents the method of automatic detection of carbon monoxide (CO) concentration. The exhaust on monoxide toxic gas. Therefore, regulations stipulate that every closed

colour, taste, smell and air. buffers and the biggest air pollutants

The exhaust gases of internal combustion engines are one of the biggest atmospheric pollutants with this duction of iron, coal combustion in thermal power plants

The automatic detection system can detect at the same time and several different gases, with an adequate to the new technology in the design of the central and gas sensors, the system has a high

sensitivity and fast response. When the gas concentration reaches or exceeds the set alarm levels, the outputs for the desired executive functions

This work is a contribution to the Ministry of Education, Science and Technological Development, Republic of


STATIC STRENGTH ANAL

STRUCTURE OF BIOMASS

HYDROSTATIC PRESSUREJovan D. Tanaskovic

1University of Belgrade, Faculty of Mechanical Engineering, Department of Rai

2University of Belgrade, Faculty of Mechanical Engineering, Department of Process Engineering and Environment Protection, 11000 Belgrade, Serbia


Abstract

Subject of this paper is numerical analysis of the steel structure of biomass reservoir under hydrostatic pressure as well as additional loads. Reservoir was made from steel grade S235 and presents disassembly construction which contains eight walls of height of 5.5 meters placed on the floor in diameter of 10 meters. The floor is supported on eight legs along the scope and on the four center legs. Static strength analysis was performed by finite element method using 3D modanalysed: a) hydrostatic pressure obtained by water to the height of 5 meters, b) hydrostatic pressure and snow force on the upper flange of 5.9 kN and c) hydrostatic pressure and biogas pressure on under 8 mbar. Numerical results showed that the structure is not correctly defined. Maximal values of stresses are much higher than allowed for the steel S235, especially in the floor construction and on the joins between the walls and the floor. Reconstruction of the reservoir was suggested. The floor is reinforced by the under frame made from tubes of rectangle cross section and with additional supports in the central zone. These modifications gave lower values of the stresses. However, for use of fulincrease thickness of steel cover of the floor and the walls on the height of 1 meter from the floor. Without any changes of the steel construction, producer decided to use reservoir with capacity of 1/5 of full (1m height of water) and moved prototype to farm where assembly of them started.

Keywords

Biomass, Finite Element Method, Hydrostatic Pressure, Static Strength Analysis, Biogas

Acknowledgement

The research work is funded by the Ministry of Education, Science aRepublic of Serbia, Projects TR35045 and TR35031.



Zlatibor, July 0


STATIC STRENGTH ANALYSES OF THE STEEL

STRUCTURE OF BIOMASS RESERVOIR UNDER

HYDROSTATIC PRESSURE Jovan D. Tanaskovic1*, Martina M. Balac2

University of Belgrade, Faculty of Mechanical Engineering, Department of Rail Vehicles, 11000 Belgrade, Serbia

University of Belgrade, Faculty of Mechanical Engineering, Department of Process Engineering and Environment Protection, 11000 Belgrade, Serbia


Subject of this paper is numerical analysis of the steel structure of biomass reservoir under hydrostatic pressure as well as additional loads. Reservoir was made from steel grade S235 and presents disassembly

which contains eight walls of height of 5.5 meters placed on the floor in diameter of 10 meters. The floor is supported on eight legs along the scope and on the four center legs. Static strength analysis was performed by finite element method using 3D model obtained by the producer. Three load cases were

: a) hydrostatic pressure obtained by water to the height of 5 meters, b) hydrostatic pressure and snow force on the upper flange of 5.9 kN and c) hydrostatic pressure and biogas pressure on under 8 mbar. Numerical results showed that the structure is not correctly defined. Maximal values of stresses are much higher than allowed for the steel S235, especially in the floor construction and on the joins between the

struction of the reservoir was suggested. The floor is reinforced by the under frame made from tubes of rectangle cross section and with additional supports in the central zone. These modifications gave lower values of the stresses. However, for use of full capacity of reservoir is necessary to increase thickness of steel cover of the floor and the walls on the height of 1 meter from the floor. Without any changes of the steel construction, producer decided to use reservoir with capacity of 1/5 of full (1m height of water) and moved prototype to farm where assembly of them started.


The research work is funded by the Ministry of Education, Science and Technological Development of Republic of Serbia, Projects TR35045 and TR35031.

6





YSES OF THE STEEL

RESERVOIR UNDER

l Vehicles, 11000 Belgrade,

University of Belgrade, Faculty of Mechanical Engineering, Department of Process Engineering and

Subject of this paper is numerical analysis of the steel structure of biomass reservoir under hydrostatic pressure as well as additional loads. Reservoir was made from steel grade S235 and presents disassembly

which contains eight walls of height of 5.5 meters placed on the floor in diameter of 10 meters. The floor is supported on eight legs along the scope and on the four center legs. Static strength analysis was

el obtained by the producer. Three load cases were : a) hydrostatic pressure obtained by water to the height of 5 meters, b) hydrostatic pressure and

snow force on the upper flange of 5.9 kN and c) hydrostatic pressure and biogas pressure on under flange of 8 mbar. Numerical results showed that the structure is not correctly defined. Maximal values of stresses are much higher than allowed for the steel S235, especially in the floor construction and on the joins between the

struction of the reservoir was suggested. The floor is reinforced by the under frame made from tubes of rectangle cross section and with additional supports in the central zone. These

l capacity of reservoir is necessary to increase thickness of steel cover of the floor and the walls on the height of 1 meter from the floor. Without any changes of the steel construction, producer decided to use reservoir with capacity of 1/5 of full (1m


nd Technological Development of


Invited lecture

NUMERICAL AND EXPERI

STRENGTH OF STRUCTUR

1University of Montenegro, Faculty of Mechanical Engine


Abstract

In this paper is presented the summary of investigation about the numerical and experimental analysistrength of structural elements in Hydro experimental part. In the numerical part of investigation FEM will be applied for to obtain the values of stresses and strains in the specified spots andof the structural elements. In the experimental part of investigation, experiments will be conducted in both laboratory and exploitation conditions, to confirm the values obtained through tbased on the three significant directions. These are: 1) values of stress and strain in the specified parts of the pipeline 2) values of vibrations and dynamic loads, in the turbine rotor, and shaft,3) dilatations in the pipeline caused by temperature changes in the pipeline environment.

Keywords

FEM, stresses, strains, Hydro - power plants, experimental analysis



Zlatibor, July 0


NUMERICAL AND EXPERIMENTAL ANALYSIS OF

STRENGTH OF STRUCTURAL ELEMENTS IN HYDRO

POWER PLANTS Stefan G. Culafic1*,

University of Montenegro, Faculty of Mechanical Engineering, Department of Applied Mechanics, 20000 Podgorica, Montenegro


presented the summary of investigation about the numerical and experimental analysistrength of structural elements in Hydro - power plants. The investigation contains numerical and experimental part. In the numerical part of investigation FEM will be applied for to obtain the values of stresses and strains in the specified spots and characteristic strips which will be recognized as critical places of the structural elements. In the experimental part of investigation, experiments will be conducted in both laboratory and exploitation conditions, to confirm the values obtained through the FEM. Investigation will be based on the three significant directions. These are: 1) values of stress and strain in the specified parts of the pipeline 2) values of vibrations and dynamic loads, in the turbine rotor, and shaft,

peline caused by temperature changes in the pipeline environment.

power plants, experimental analysis

7





MENTAL ANALYSIS OF

AL ELEMENTS IN HYDRO -

ering, Department of Applied Mechanics, 20000

presented the summary of investigation about the numerical and experimental analysis of power plants. The investigation contains numerical and

experimental part. In the numerical part of investigation FEM will be applied for to obtain the values of characteristic strips which will be recognized as critical places

of the structural elements. In the experimental part of investigation, experiments will be conducted in both he FEM. Investigation will be

peline caused by temperature changes in the pipeline environment.


Invited lecture

THE SOLAR MEASUREMEN

EXAMINATION OF THE T

Mirko Dobrnjac1University of Banjaluka, Faculty of Mechanical Engineering, 78000 Banjaluka, Bosnia and Herzegovina


Abstract

The use of renewable energy sources is becoming increasingly apparent, including solar energy, which is directly or indirectly the only source of life on Earth. Monitoring of the manifestation of solar radiation and the exploitation of this type of energy predominantly imposes the need trelated to radiation itself, as well as radiation receivers and other devices of the system. Thermal receivers with liquid as a solar energy transmitter have now become consumer goods with a large number of manufacturers. Their examination is important with several aspects; from scientific research, for their further research and development, but also from the perspective of consumers, as they obtain reliable information on the quality of solar collectors, on the basis of whpaper is to examine one design of the measurement station for testing solar collectors with all components, as well as presenting possible test methods according to the standard SRPS M.F5.050.a solar measuring station where the described measuring devices are used for measuring the parameters in the operation of the solar thermal panel and give examples of the presentation of the processed results.

Keywords

Heat transfer, solar collector, measurement station, energy efficiency, solar energy



Zlatibor, July 0


THE SOLAR MEASUREMENT STATION FOR

EXAMINATION OF THE THERMAL RECEIVER FOR

SOLAR ENERGY Mirko Dobrnjac1*, Milos Markovic1,

University of Banjaluka, Faculty of Mechanical Engineering, 78000 Banjaluka, Bosnia and Herzegovina


ces is becoming increasingly apparent, including solar energy, which is directly or indirectly the only source of life on Earth. Monitoring of the manifestation of solar radiation and the exploitation of this type of energy predominantly imposes the need to measure a number of parameters related to radiation itself, as well as radiation receivers and other devices of the system. Thermal receivers with liquid as a solar energy transmitter have now become consumer goods with a large number of

heir examination is important with several aspects; from scientific research, for their further research and development, but also from the perspective of consumers, as they obtain reliable information on the quality of solar collectors, on the basis of which they choose the most optimal solution. The aim of the

to examine one design of the measurement station for testing solar collectors with all components, as well as presenting possible test methods according to the standard SRPS M.F5.050.a solar measuring station where the described measuring devices are used for measuring the parameters in the operation of the solar thermal panel and give examples of the presentation of the processed results.

llector, measurement station, energy efficiency, solar energy

8





T STATION FOR

HERMAL RECEIVER FOR

University of Banjaluka, Faculty of Mechanical Engineering, 78000 Banjaluka, Bosnia and Herzegovina

ces is becoming increasingly apparent, including solar energy, which is directly or indirectly the only source of life on Earth. Monitoring of the manifestation of solar radiation and the

o measure a number of parameters related to radiation itself, as well as radiation receivers and other devices of the system. Thermal receivers with liquid as a solar energy transmitter have now become consumer goods with a large number of

heir examination is important with several aspects; from scientific research, for their further research and development, but also from the perspective of consumers, as they obtain reliable information

ich they choose the most optimal solution. The aim of the to examine one design of the measurement station for testing solar collectors with all components,

as well as presenting possible test methods according to the standard SRPS M.F5.050. The paper presents a solar measuring station where the described measuring devices are used for measuring the parameters in the operation of the solar thermal panel and give examples of the presentation of the processed results.


COMPARISON BETWEEN D

PROCEDURES OF LOADS

DILATATION IN PIPELIMilan Travica

1University of Belgrade, Innovation Center of Faculty of Mechanical Engineering,2University of Belgrade, Faculty of Mechanical Engineering, Department of Process technique and

environmental protection, 11000 Belgrade, Serbia


Abstract

The problem of loads caused by the temperature dilatations in pipes and its effect on strain and stress state of the entire pipeline is common problem in engineering practice. This paper dcalculation of loads that can occur in the pipeline caused by temperature differences. The study presented in the paper analysed the L shaped pipeline configuration with an operating temperature at 200material P235GH, angle between legs of the L shaped pipeline is 90pressure is 10bar (absolute pressure). The calculation was presented according to standards EN 13480and AD 2000 and Russian method commonly used in engineering pradifferent engineering approaches for solving the same type of the problem, so the specific differences were presented in the paper. All the results are presented in unified tables for easier comparison and analysis. It can be conducted that all three presented methods showed similar results and choosing the most suitable one for the practical application is mainly determined by the type of the result needed for the specific application.

Keywords

Temperature dilatation; L shaped pipeline configuration; standards, EN13480



Zlatibor, July 0


COMPARISON BETWEEN DIFFERENT CALCULATION

PROCEDURES OF LOADS CAUSED BY TEMPERATUR

DILATATION IN PIPELINES Milan Travica1*, Nenad Mitrovic2, Aleksandar Petrovic2

vation Center of Faculty of Mechanical Engineering, 11000 Belgrade, Serbia

University of Belgrade, Faculty of Mechanical Engineering, Department of Process technique and environmental protection, 11000 Belgrade, Serbia


The problem of loads caused by the temperature dilatations in pipes and its effect on strain and stress state of the entire pipeline is common problem in engineering practice. This paper describes three calculation of loads that can occur in the pipeline caused by temperature differences. The study presented in the paper analysed the L shaped pipeline configuration with an operating temperature at 200

, angle between legs of the L shaped pipeline is 90⁰, pipe dimension DN 300 and operating pressure is 10bar (absolute pressure). The calculation was presented according to standards EN 13480and AD 2000 and Russian method commonly used in engineering practice. The three methods have different engineering approaches for solving the same type of the problem, so the specific differences were presented in the paper. All the results are presented in unified tables for easier comparison and analysis. It

presented methods showed similar results and choosing the most suitable one for the practical application is mainly determined by the type of the result needed for the specific

pipeline configuration; standards, EN13480-3; AD 2000;

9





IFFERENT CALCULATION

CAUSED BY TEMPERATURE

11000 Belgrade, Serbia

University of Belgrade, Faculty of Mechanical Engineering, Department of Process technique and

The problem of loads caused by the temperature dilatations in pipes and its effect on strain and stress state escribes three methods for

calculation of loads that can occur in the pipeline caused by temperature differences. The study presented in the paper analysed the L shaped pipeline configuration with an operating temperature at 200

oC, pipeline

, pipe dimension DN 300 and operating pressure is 10bar (absolute pressure). The calculation was presented according to standards EN 13480-3

ctice. The three methods have different engineering approaches for solving the same type of the problem, so the specific differences were presented in the paper. All the results are presented in unified tables for easier comparison and analysis. It

presented methods showed similar results and choosing the most suitable one for the practical application is mainly determined by the type of the result needed for the specific

3; AD 2000; Russian method


Invited lecture

INNOVATION MANAGEMEN

1University of Belgrade, Innovation center of Faculty of Serbia,


Abstract

Management is highly important function in today’s dynamic business environment. Many historical milestones have shaped management process, scientific management, serial production at Ford's factories, the human relations movement, management science, reengineering, flexibility, computer age, timeand environmental issues. Globalization enabled creation of global supply chains, creation of new worldclass organizations and unions and brought great competition. International trade barriers have fallen. And new trade agreements have created. The aim of this paper is to present lean approach as a modern production system developed by Toyota Motor Corporation in order to ensure best quality, lowest prices and shorter preparation periods by eliminating unnecessary costs. Toyota managers shiindividual machines and their utilization, to the flow of the product through the total process. They concluded that by right-sizing machines for the real volume needed, introducing pull production system, machines to ensure quality, lining the machines up in process section, and having each process step notify the previous step of its current needs for materials.

Keywords

Innovation management; Lean approach; modern production system



Zlatibor, July 0


INNOVATION MANAGEMENT- LEAN ENTERPRISE1Snezana Kirin

center of Faculty of Mechanical Engineering, KraljiceSerbia, ORCID: 0000-0002-2176-3969


Management is highly important function in today’s dynamic business environment. Many historical milestones have shaped management process. Some of these are the Industrial Revolution, Bessemer process, scientific management, serial production at Ford's factories, the human relations movement, management science, reengineering, flexibility, computer age, time-based competition, globaland environmental issues. Globalization enabled creation of global supply chains, creation of new worldclass organizations and unions and brought great competition. International trade barriers have fallen. And

ted. The aim of this paper is to present lean approach as a modern production system developed by Toyota Motor Corporation in order to ensure best quality, lowest prices and shorter preparation periods by eliminating unnecessary costs. Toyota managers shifted the focus of the manufacturing engineer from individual machines and their utilization, to the flow of the product through the total process. They concluded

sizing machines for the real volume needed, introducing pull production system, machines to ensure quality, lining the machines up in process section, and having each process step notify the previous step of its current needs for materials.

Innovation management; Lean approach; modern production system

10





LEAN ENTERPRISE

, Kraljice Marije 16, Belgrade,

Management is highly important function in today’s dynamic business environment. Many historical process. Some of these are the Industrial Revolution, Bessemer

process, scientific management, serial production at Ford's factories, the human relations movement, based competition, global marketplace,

and environmental issues. Globalization enabled creation of global supply chains, creation of new world-class organizations and unions and brought great competition. International trade barriers have fallen. And

The aim of this paper is to present lean approach as a modern production system developed by Toyota Motor Corporation in order to ensure best quality, lowest prices and shorter preparation periods by

fted the focus of the manufacturing engineer from individual machines and their utilization, to the flow of the product through the total process. They concluded

sizing machines for the real volume needed, introducing pull production system, self-monitoring machines to ensure quality, lining the machines up in process section, and having each process step notify


IDENTIFICATION AND RECO

ENVIRONMENT USING AR

Darko Jocic1University of Belgrade, Innovation center of Faculty of Mechanical Engineering, Kraljice


Abstract

Object detection using deep learning over the years became one of the most popular implementation in autonomous systems. Autonomous vehicle requiidentification and recognition of surrounding objects in real traffic environments to achieve decent detection results. In this paper, special type of Artificial Neural Network (ANN) named Convolutional Neural Network (CNN) was used for identification and recognition of surrounding objects in real traffic. The new model based on CNN was trained and developed to be able to identify and recognize 4 different classes of objects: cars, traffic lights, persons and bicycles. The deand recognizing on the test set.

Keywords

Artificial Neural Networks, Convolutional Neural Network, Object Detection,



Zlatibor, July 0


NTIFICATION AND RECOGNITION OF VEHICLE

ENVIRONMENT USING ARTIFICIAL NEURAL

NETWORKS Darko Jocic1, Velimir Cirovic1, Dragan Aleksendric1

University of Belgrade, Innovation center of Faculty of Mechanical Engineering, KraljiceSerbia

orresponding author e-mail: [email protected]

Object detection using deep learning over the years became one of the most popular implementation in autonomous systems. Autonomous vehicle requires very reliable and accurate identification and recognition of surrounding objects in real traffic environments to achieve decent detection results. In this paper, special type of Artificial Neural Network (ANN) named Convolutional Neural Network

as used for identification and recognition of surrounding objects in real traffic. The new model based was trained and developed to be able to identify and recognize 4 different classes of objects: cars,

persons and bicycles. The developed model has shown 94.6% accuracy of object identification

Artificial Neural Networks, Convolutional Neural Network, Object Detection, Vehicles Environment

11





GNITION OF VEHICLE

TIFICIAL NEURAL

University of Belgrade, Innovation center of Faculty of Mechanical Engineering, Kraljice Marije 16, Belgrade,

Object detection using deep learning over the years became one of the most popular methods for res very reliable and accurate

identification and recognition of surrounding objects in real traffic environments to achieve decent detection results. In this paper, special type of Artificial Neural Network (ANN) named Convolutional Neural Network

as used for identification and recognition of surrounding objects in real traffic. The new model based was trained and developed to be able to identify and recognize 4 different classes of objects: cars,

veloped model has shown 94.6% accuracy of object identification

Vehicles Environment


DESIGN STUDY OF

Boris Kosic1, Misa Stojicevic1, Zorana Jeli1University of Belgrade, Faculty of Mechanical Engineering, Department of Information Technologies, 11000


Abstract

Different geometry of metameterials has ability to withstand a certain level of deformation, and is used to replace joints in certain assemblies of technical systems. Using this characteristimovements could be accomplished with deformation of technical system structures.This paper cover examination on two different kind of geometry structure of metamaterials, regular and irregular octagon, and the influence of technical systems. A larger number of simulations have been conducted by changing internal structure and orientation of metamaterials. Also, those metametarials have been used on some of the model of Further, the pliers models were simulated, and results were compared with the results from previous simulations. For each simulation the results were presented as stresses and displacements with the same load, but different direction of force. been used for simulation, design of the 3D models and whole study. using design study, define the level of deformation which structures can withstand, andgave the ideas for methodology of the concept for pre

Keywords:

3D model, metamaterial, design study, Solid

Acknowledgement

This work was financially supported by the Ministry of ScienceRepublic of Serbia through project No. TR 35011.



Zlatibor, July 0


DESIGN STUDY OF THE DIFERENT METAMATERIA

SHAPES , Zorana Jeli1, Branislav Pokonstantinovic1, Aleksandra Dragicevic

University of Belgrade, Faculty of Mechanical Engineering, Department of Information Technologies, 11000 Belgrade, Serbia


Different geometry of metameterials has ability to withstand a certain level of deformation, and is used to replace joints in certain assemblies of technical systems. Using this characteristimovements could be accomplished with deformation of technical system structures.

paper cover examination on two different kind of geometry structure of metamaterials, regular and the influence of their geometrical structures, as a new concepts for formation of

A larger number of simulations have been conducted by changing internal structure and orientation of metamaterials. Also, those metametarials have been used on some of the model of

, the pliers models were simulated, and results were compared with the results from previous For each simulation the results were presented as stresses and displacements with the same

load, but different direction of force. SOLIDWORKS 2016, as a powerful tool for this kind of analysis, had been used for simulation, design of the 3D models and whole study. The results obtained from simulations, using design study, define the level of deformation which structures can withstand, andgave the ideas for methodology of the concept for preparing geometry of metametrials

3D model, metamaterial, design study, Solid Works, simulation

This work was financially supported by the Ministry of Science and Technological Development of the Republic of Serbia through project No. TR 35011.

12





DIFERENT METAMATERIAL

, Aleksandra Dragicevic1

University of Belgrade, Faculty of Mechanical Engineering, Department of Information Technologies, 11000

Different geometry of metameterials has ability to withstand a certain level of deformation, and is used to replace joints in certain assemblies of technical systems. Using this characteristic of metametrials, all

paper cover examination on two different kind of geometry structure of metamaterials, regular and

as a new concepts for formation of A larger number of simulations have been conducted by changing internal structure and

orientation of metamaterials. Also, those metametarials have been used on some of the model of pliers. , the pliers models were simulated, and results were compared with the results from previous

For each simulation the results were presented as stresses and displacements with the same DWORKS 2016, as a powerful tool for this kind of analysis, had

The results obtained from simulations, using design study, define the level of deformation which structures can withstand, and therewithal, they

paring geometry of metametrials.

and Technological Development of the


THE NEW METHOD FOR R

CORRELATED VARIABLESAleksandra Dragicevic

1University of Belgrade, Faculty of Mechanica


Abstract

Reducing of the data dimensionality is necessary and required for optimal model performance in machine learning. Two different approaches, frequently used in practice to solve this problem, were considered with the aim to build the new one. The basic idea of the first approach is to reduce dimensionality by removing highly correlated variables which implies thatphenomenon that has been observed. It is done by removing all variables with high average correlation. In this way, variables are removed regardless to its significance to model accuracy, and as a reaccuracy can noticeably drop. The second approach implies necessary quantification of variable impact on model outcome and to sort them according to these values for the better understanding of the data, relationship between variables and the model outcome. By using this approach, variables with lowest importance are removed from the data set, and can lead to an increasing in the performance and accuracy of the final model.In the datasets with the highly correlated variables (e.g. sets of spectrvariables can be with the highest average correlation, and after removing those variables the accuracy of the model can be significantly reduced. Based on the previous facts, the new method that uses the most important variables with lowest correlation is proposed, as a combination of the previous two approaches. The main idea of this approach is to notably reduce dataset dimensionality using the variables that have small correlation and where the accuracy remains high.

Keywords

Machine learning, highly correlated data, variable importance, data dimensionality



Zlatibor, July 0


THE NEW METHOD FOR REMOVING HIGHLY

CORRELATED VARIABLES FROM DATASETSAleksandra Dragicevic1, Boris Kosic1, Zorana Jeli1

University of Belgrade, Faculty of Mechanical Engineering, 11000 Belgrade, Serbia


Reducing of the data dimensionality is necessary and required for optimal model performance in machine ing. Two different approaches, frequently used in practice to solve this problem, were considered with

the aim to build the new one. The basic idea of the first approach is to reduce dimensionality by removing highly correlated variables which implies that multiple variables measure the same characteristic of a phenomenon that has been observed. It is done by removing all variables with high average correlation. In this way, variables are removed regardless to its significance to model accuracy, and as a re

The second approach implies necessary quantification of variable impact on model outcome and to sort them according to these values for the better understanding of the data, relationship between variables and the

del outcome. By using this approach, variables with lowest importance are removed from the data set, and can lead to an increasing in the performance and accuracy of the final model. In the datasets with the highly correlated variables (e.g. sets of spectroscopy data), the most important variables can be with the highest average correlation, and after removing those variables the accuracy of the model can be significantly reduced. Based on the previous facts, the new method that uses the most

ables with lowest correlation is proposed, as a combination of the previous two approaches. The main idea of this approach is to notably reduce dataset dimensionality using the variables that have small correlation and where the accuracy remains high.

Machine learning, highly correlated data, variable importance, data dimensionality

13





EMOVING HIGHLY

FROM DATASETS

l Engineering, 11000 Belgrade, Serbia

Reducing of the data dimensionality is necessary and required for optimal model performance in machine ing. Two different approaches, frequently used in practice to solve this problem, were considered with

the aim to build the new one. The basic idea of the first approach is to reduce dimensionality by removing multiple variables measure the same characteristic of a

phenomenon that has been observed. It is done by removing all variables with high average correlation. In this way, variables are removed regardless to its significance to model accuracy, and as a result model

The second approach implies necessary quantification of variable impact on model outcome and to sort them according to these values for the better understanding of the data, relationship between variables and the

del outcome. By using this approach, variables with lowest importance are removed from the data set,

oscopy data), the most important variables can be with the highest average correlation, and after removing those variables the accuracy of the model can be significantly reduced. Based on the previous facts, the new method that uses the most

ables with lowest correlation is proposed, as a combination of the previous two approaches. The main idea of this approach is to notably reduce dataset dimensionality using the variables that have

14

Materials Science


ANALYSING SAMPLES AN

Ivan Tanasic

1 University of Belgrade, Faculty for Dental Medici


Abstract

In vitro experiments include proper materials whether human’s or humans’ substituents to avoid invasclinical procedures. In such cases, researchers can use blood, urine or some other stuff but try to close in vitro conditions to in vivo-physiological conditions as much as possible. Following study intended to show examples of the samples and specimenconsideration. In experimental investigation, specimen is considered as an individual issue that represents a class while sample is a part of anything taken or presented for inspection, or shown quality of the whole. The aim of this report was to represent differences between sample and specimen in dentistry research and to show the possibilities of biomechanical investigation of these materials used for in vitro setup. In dental biomechanics, cadaveric teeth and bone, bone substituents artificial membrane, strips/bands, saliva and replacements made for various indications can be used for the purpose of biomechanical analysis. Determination and measuring of strain in these biomatin the interpretation of the results presented in this biomedical report. Differences were shown in the methodological approach involved preparation of specimens/samples and loading conditions. Findings provide that all of these tissues and artificial organs can serve for investigations in dental biomechanics if adequate conditions are conducted. Nevertheless, human cadaveric tissues were found to be the best choice when considered achieving of physiological conditions.

Keywords

Biomaterials, dental samples, biomechanical analysis, cadaveric specimen, artificial organs and tissues



Zlatibor, July 0

Materials Science

ANALYSING SAMPLES AND SPECIMENS IN DENTA

BIOMECHANICS Ivan Tanasic1*, Ljiljana Tihacek Sojic1

1 University of Belgrade, Faculty for Dental Medicine, Depatment for Prosthodontics, 11000 Belgrade


In vitro experiments include proper materials whether human’s or humans’ substituents to avoid invasclinical procedures. In such cases, researchers can use blood, urine or some other stuff but try to close in

physiological conditions as much as possible. Following study intended to show examples of the samples and specimens application in dentistry research field with biomechanical

In experimental investigation, specimen is considered as an individual issue that represents a class while sample is a part of anything taken or presented for inspection, or shown

The aim of this report was to represent differences between sample and specimen in dentistry research and to show the possibilities of biomechanical investigation of these materials used for in

l biomechanics, cadaveric teeth and bone, bone substituents artificial membrane, strips/bands, saliva and replacements made for various indications can be used for the purpose of biomechanical analysis. Determination and measuring of strain in these biomaterials was the main criterion in the interpretation of the results presented in this biomedical report. Differences were shown in the methodological approach involved preparation of specimens/samples and loading conditions. Findings

se tissues and artificial organs can serve for investigations in dental biomechanics if adequate conditions are conducted. Nevertheless, human cadaveric tissues were found to be the best choice when considered achieving of physiological conditions.


15




Materials Science

D SPECIMENS IN DENTAL

ne, Depatment for Prosthodontics, 11000 Belgrade

In vitro experiments include proper materials whether human’s or humans’ substituents to avoid invasive clinical procedures. In such cases, researchers can use blood, urine or some other stuff but try to close in

physiological conditions as much as possible. Following study intended to show s application in dentistry research field with biomechanical

In experimental investigation, specimen is considered as an individual issue that represents a class while sample is a part of anything taken or presented for inspection, or shown as evidence of the

The aim of this report was to represent differences between sample and specimen in dentistry research and to show the possibilities of biomechanical investigation of these materials used for in

l biomechanics, cadaveric teeth and bone, bone substituents artificial membrane, strips/bands, saliva and replacements made for various indications can be used for the purpose of

erials was the main criterion in the interpretation of the results presented in this biomedical report. Differences were shown in the methodological approach involved preparation of specimens/samples and loading conditions. Findings

se tissues and artificial organs can serve for investigations in dental biomechanics if adequate conditions are conducted. Nevertheless, human cadaveric tissues were found to be the best



TGA AND DTA ANALYSIS

BASED ON POLY (HYDRO

Aleksandra D. Mitrovic1*, Aleksandra

*1University of Belgrade, Faculty of Technology and Metallurgy, Belgrade, Serbia2University of Belgrade, Faculty of Mechanical Engineering,3University of Belgrade, Vinča

4Soleko, 1 Via Ravano, 03037 Pontecorvo (Frosinone), Italy5University of Belgrade, Faculty for Special Education and Rehabilitation, Belgrade, Serbia

* Corresponding author e

Abstract

Hydrogels have emerged as effective materials for variety of applications due to unique network structure that enables very high levels of hydrophilicity and biocompatibility. Hydrogelsmethacrylate (HEMA) are of a great interest in biomedical applications.hydrogel lenses are still the most popular type of soft contact lens. The aim of this paper is comparative thermal stability study of the basic material and nanophotonic materials synthesized by the company Soleco (Milan, Italy). The basic and nanophotonic materials for soft contact lenses were obtained using radical polymerization of 2-hydroxyethyl methacrylate respectively i.e. fullerol andfullerene metformin hydroxylateand properties. For soft contact lenses thermal analysis, Differential thermal analysisgravimetric analysis (TG) were used. have shown that the thermal stability of nanophotonic materialsbasic material. Further research is necesmaterials for soft contact lenses.

Keywords

Fullerenes, HEMA, soft contact lenses, nanophotonic materials, thermal analysis

Acknowledgement

The authors are grateful to Optix (Belgrade, Serbia) ain this study.



Zlatibor, July 0

Materials Science

TGA AND DTA ANALYSIS OF SOFT CONTACT LENS

BASED ON POLY (HYDROXYETHYL METHACRYLATE

AND FULLERENES Aleksandra Lj. Dragicevic2, Dejana P. Popovic3, Manuel Conte

M. Stamenkovic5

University of Belgrade, Faculty of Technology and Metallurgy, Belgrade, Serbia

University of Belgrade, Faculty of Mechanical Engineering, Belgrade,

University of Belgrade, Vinča Institute of Nuclear Sciences, Belgrade, Serbia

Soleko, 1 Via Ravano, 03037 Pontecorvo (Frosinone), Italy

University of Belgrade, Faculty for Special Education and Rehabilitation, Belgrade, Serbia

* Corresponding author e-mail: [email protected]

Hydrogels have emerged as effective materials for variety of applications due to unique network structure that enables very high levels of hydrophilicity and biocompatibility. Hydrogels based on 2methacrylate (HEMA) are of a great interest in biomedical applications. Hydroxyethyl methacrylatehydrogel lenses are still the most popular type of soft contact lens. The aim of this paper is comparative

udy of the basic material and nanophotonic materials synthesized by the company Soleco (Milan, Italy). The basic and nanophotonic materials for soft contact lenses were obtained using radical

hydroxyethyl methacrylate respectively i.e. 2-hydroxyethyl methacrylate and fullerene, fullerene metformin hydroxylate, respectively. Fullerenes were used due to theirs unique structure

For soft contact lenses thermal analysis, Differential thermal analysis(TG) were used. The thermal properties of all four materials were examined.

have shown that the thermal stability of nanophotonic materials is significantly improved comparing to the basic material. Further research is necessary to show if it is possible to develop a new generation of

Fullerenes, HEMA, soft contact lenses, nanophotonic materials, thermal analysis

The authors are grateful to Optix (Belgrade, Serbia) and Soleko (Milano, Italy) for providing the material used

16




Materials Science

OF SOFT CONTACT LENSES

XYETHYL METHACRYLATE)

, Manuel Conte4, Dragomir


Belgrade, Serbia

Institute of Nuclear Sciences, Belgrade, Serbia


[email protected]

Hydrogels have emerged as effective materials for variety of applications due to unique network structure based on 2-hydroxyethyl

Hydroxyethyl methacrylate based hydrogel lenses are still the most popular type of soft contact lens. The aim of this paper is comparative

udy of the basic material and nanophotonic materials synthesized by the company Soleco (Milan, Italy). The basic and nanophotonic materials for soft contact lenses were obtained using radical

hydroxyethyl methacrylate and fullerene, , respectively. Fullerenes were used due to theirs unique structure

For soft contact lenses thermal analysis, Differential thermal analysis (DTA) and Thermo The thermal properties of all four materials were examined. Results

improved comparing to the sary to show if it is possible to develop a new generation of

nd Soleko (Milano, Italy) for providing the material used


EXPLORATION OF THE C

WATER VAPOUR RESISTA

DURING MAINTENANCEReljic M. Mirjana1,3*, Stojiljkovic T. Stanisa

2 Faculty of Technology, University of Niš, Leskovac, Serbia3The College of Textile

* Corresponding author e

Abstract

Human thermal comfort depends on the combination of clothes, climate conditions and physical activity. Clothing maintenance by washing affects its diffusion and thermal properties. Water vapour pthermal resistance of clothing are key parameters for the assessment of clothing during exploitation wearing. The paper examined the interrelatedness of physical, mechanical and properties of fabrics as well as changeduring washing of 6 fabrics used for making clothing assemblies (for particular conditions of application). Standard methods were applied for examining physical and mechanical properties plate measurements were used for testing water vapour resistance (Rcertain properties yarns used in the production of fabrics and constructional characteristics of fabrics significantly affect the water vapour resistance and its changes during washing. The results were used for establishing a mathematical model for predicting the behaviour of the fabrics during washing that are used for a particular clothing assembly in the phase of exploitati

Keywords

Textile materials, water vapour resistance, thermal resistance, hot plate, thermal comfort



Zlatibor, July 0

Materials Science

EXPLORATION OF THE CHANGES OF PROPERTIES

WATER VAPOUR RESISTANCE OF CO/PES FABRIC

DURING MAINTENANCE , Stojiljkovic T. Stanisa2, Stepanovic M. Jovan2, Lazic B. Branislava

Stojiljkovic2 1CIS Institute, Belgrade, Serbia

Faculty of Technology, University of Niš, Leskovac, Serbia

The College of Textile - Design, Technology and Management, Belgrade, Serbia

* Corresponding author e-mail: [email protected]

Human thermal comfort depends on the combination of clothes, climate conditions and physical activity. Clothing maintenance by washing affects its diffusion and thermal properties. Water vapour pthermal resistance of clothing are key parameters for the assessment of clothing during exploitation wearing. The paper examined the interrelatedness of physical, mechanical and properties of fabrics as well as changes of a thermo physiological property – water vapour resistance (Rduring washing of 6 fabrics used for making clothing assemblies (for particular conditions of application). Standard methods were applied for examining physical and mechanical properties plate measurements were used for testing water vapour resistance (Ret). The obtained results indicated that certain properties yarns used in the production of fabrics and constructional characteristics of fabrics

t the water vapour resistance and its changes during washing. The results were used for establishing a mathematical model for predicting the behaviour of the fabrics during washing that are used for a particular clothing assembly in the phase of exploitation – wearing.


17




Materials Science

HANGES OF PROPERTIES OF

NCE OF CO/PES FABRICS

c B. Branislava3, Milena S.

Design, Technology and Management, Belgrade, Serbia

Human thermal comfort depends on the combination of clothes, climate conditions and physical activity. Clothing maintenance by washing affects its diffusion and thermal properties. Water vapour permeability and thermal resistance of clothing are key parameters for the assessment of clothing during exploitation – wearing. The paper examined the interrelatedness of physical, mechanical and thermo physiological

water vapour resistance (Ret) during washing of 6 fabrics used for making clothing assemblies (for particular conditions of application). Standard methods were applied for examining physical and mechanical properties of fabrics, whereas hot

). The obtained results indicated that certain properties yarns used in the production of fabrics and constructional characteristics of fabrics

t the water vapour resistance and its changes during washing. The results were used for establishing a mathematical model for predicting the behaviour of the fabrics during washing that are used



EXPERIMENTAL STUDY O

USING 3D DIGITAL IMAAleksandra Mitrovic*1, Nenad Mitrovic

*1University of Belgrade, Faculty of Technology and Metallurgy, Karnegijeva 4, Belgrade, Serbia2University of Belgrade, Faculty of Mechanical Engineering, Kraljice

3University of Belgrade, Vinca Institute, Mike Petrovića4Innovation Center of Faculty of Mechanical Engineering, Kraljice

5Omya International AG, Neuhofstrasse 11, CH

*Corresponding author; e

Abstract

Textiles are unique due to their structure and formability properties. In order to predict the properties of textile materials, standard invesdetailed study is performed and additional results were obtained when the 3D Digital Image Correlation (DIC) method was adjusted to the standard test method. The digital image analysis methoproposed methods used to determine textile deformation localized deformation zones, besides capturing the deformation of the woven fabric. The procedure of digital video camera recording is simple, but preparation and processing on a computer are relatively demanding concerning processing time and data preparation for analysis. The processing time for displacement calculation depends on the image resolution, number of images, chosennumber of facet centers and characteristics of the computer used for results processing. Obtained results are adequate and satisfy the requirements of accuracy applied to material science. Therefore, the application of the image analysis method for the investigation of deformed textile materials is possible.

Keywords

Textile, deformation, 3D Digital Image Correlation Method

Acknowledgement

This research was supported by Ministry of Education, Science and Technological Devof Serbia under Projects TR35031 and TR35040.



Zlatibor, July 0

Materials Science

EXPERIMENTAL STUDY OF TEXTILE DEFORMATIO

USING 3D DIGITAL IMAGE CORRELATION METHO, Nenad Mitrovic2, Dejana Popovic3, Milos Milosevic4, Vladimir Miljkovic

University of Belgrade, Faculty of Technology and Metallurgy, Karnegijeva 4, Belgrade, Serbia

University of Belgrade, Faculty of Mechanical Engineering, Kraljice Marije 16, Belgrade, Serbia

, Vinca Institute, Mike Petrovića Alasa 12-14, Belgrade, Serbia

Innovation Center of Faculty of Mechanical Engineering, Kraljice Marije 16, Belgrade, Serbia

Omya International AG, Neuhofstrasse 11, CH-4153 Reinach, Switzerland

*Corresponding author; e-mail: [email protected]

Textiles are unique due to their structure and formability properties. In order to predict the properties of textile materials, standard investigation methods are not always sufficient. In this paper, a more detailed study is performed and additional results were obtained when the 3D Digital Image Correlation (DIC) method was adjusted to the standard test method. The digital image analysis methoproposed methods used to determine textile deformation behaviour. It is possible to capture the formation of localized deformation zones, besides capturing the deformation of the woven fabric. The procedure of digital

ording is simple, but preparation and processing on a computer are relatively demanding concerning processing time and data preparation for analysis. The processing time for displacement calculation depends on the image resolution, number of images, chosen area sizes on images for analysis, number of facet centers and characteristics of the computer used for results processing. Obtained results are adequate and satisfy the requirements of accuracy applied to material science. Therefore, the application of he image analysis method for the investigation of deformed textile materials is possible.

Textile, deformation, 3D Digital Image Correlation Method

This research was supported by Ministry of Education, Science and Technological Devof Serbia under Projects TR35031 and TR35040.

18




Materials Science

F TEXTILE DEFORMATION

GE CORRELATION METHOD , Vladimir Miljkovic5


Marije 16, Belgrade, Serbia

14, Belgrade, Serbia


4153 Reinach, Switzerland

[email protected]

Textiles are unique due to their structure and formability properties. In order to predict the behaviour and tigation methods are not always sufficient. In this paper, a more

detailed study is performed and additional results were obtained when the 3D Digital Image Correlation (DIC) method was adjusted to the standard test method. The digital image analysis method is one of the newly

. It is possible to capture the formation of localized deformation zones, besides capturing the deformation of the woven fabric. The procedure of digital

ording is simple, but preparation and processing on a computer are relatively demanding concerning processing time and data preparation for analysis. The processing time for displacement

area sizes on images for analysis, number of facet centers and characteristics of the computer used for results processing. Obtained results are adequate and satisfy the requirements of accuracy applied to material science. Therefore, the application of he image analysis method for the investigation of deformed textile materials is possible.

This research was supported by Ministry of Education, Science and Technological Development of Republic


IR SPECTROSCOPYOF TH

C84-D2:22 FOR ITS QUALITAT

T. Jovanovic1*, Dj. Koruga1,A. Mitrovi

1University of Belgrade, Faculty of Mechanical Engineering, Department of

2University of Belgrade, Faculty of Technology and Metallurgy, Belgrade, Serbia3University of Belgrade, Faculty for

4Norwegian University of Science and Technology, Trondheim, Norway5University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Department of Chemistry, 11000

*Correspon

Abstract

The stable isomer of the higher fullerene Cadvanced extraction and chromatographic methods and C84-D2:22was performed by the FT-absorption mode. A series of various characteristic, dominant and new absorption maxima of this fullerene was registered and confirmed. All the observed infrared absorption bands are in excellent agreement with the theoretical calculations for this moleculabsorptivity, ψ, of its IR absorption bands were determined in adequate and different spectral regions. These results are significant for the qualitative and quantitative determination of the Cnatural resources in space and on the Earth or in artificially synthesized materials, electronic, optical and biomedical devices, polymers, composites, catalysts, nanowires, batteries, sensors, optical limiters, solar cells, nanophotonic lenses with improved optical absorption characteristics, refraction features and wettability, diagnostic and therapeutic agents, pharmaceutical substances, such as for diabetes, targeted drug delivery, in biomedical engineering, applied optics an

Keywords

Higher fullerene C84-D2:22, IR spectroscopy, molar absorptivity, integrated molar absorptivity

Acknowledgement

The authors are grateful to the Ministry of Education, Science and Technological Development of the Republic of Serbia and to the University of Belgrade for financial support of this research (project III 45009).



Zlatibor, July 0

Materials Science

IR SPECTROSCOPYOF THE HIGHER FULLERENE

:22 FOR ITS QUALITATIVE AND QUANTITATIVE

DETERMINATION ,A. Mitrovic2, D. Stamenkovic3,M. Tomic4, J. Sakota

Cvetkovic5

University of Belgrade, Faculty of Mechanical Engineering, Department of Biomedical EngineeringBelgrade, Serbia



Norwegian University of Science and Technology, Trondheim, Norway

University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Department of Chemistry, 11000 Belgrade, Serbia


The stable isomer of the higher fullerene C84 of D2 symmetry was isolated from carbon soot by the new and advanced extraction and chromatographic methods and processes. Characterization of the isolated

-IR(KBr) method, over the relevant region from 400 to 2000 cmabsorption mode. A series of various characteristic, dominant and new absorption maxima of this fullerene

as registered and confirmed. All the observed infrared absorption bands are in excellent agreement with the theoretical calculations for this molecule. The molar absorptivity, ε, as well as the integrated molar absorptivity, ψ, of its IR absorption bands were determined in adequate and different spectral regions. These results are significant for the qualitative and quantitative determination of the C84-Dnatural resources in space and on the Earth or in artificially synthesized materials, electronic, optical and biomedical devices, polymers, composites, catalysts, nanowires, batteries, sensors, optical limiters, solar

ophotonic lenses with improved optical absorption characteristics, refraction features and wettability, diagnostic and therapeutic agents, pharmaceutical substances, such as for diabetes, targeted drug delivery, in biomedical engineering, applied optics and industry and so forth.

:22, IR spectroscopy, molar absorptivity, integrated molar absorptivity

The authors are grateful to the Ministry of Education, Science and Technological Development of the f Serbia and to the University of Belgrade for financial support of this research (project III 45009).

19




Materials Science

E HIGHER FULLERENE

IVE AND QUANTITATIVE

akota-Rosic1 and M.

Biomedical Engineering, 11120


Special Education and Rehabilitation, Belgrade, Serbia

Norwegian University of Science and Technology, Trondheim, Norway

University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Department of Chemistry, 11000

symmetry was isolated from carbon soot by the new and processes. Characterization of the isolated

IR(KBr) method, over the relevant region from 400 to 2000 cm-1

, in the absorption mode. A series of various characteristic, dominant and new absorption maxima of this fullerene

as registered and confirmed. All the observed infrared absorption bands are in excellent agreement with e. The molar absorptivity, ε, as well as the integrated molar

absorptivity, ψ, of its IR absorption bands were determined in adequate and different spectral regions. These D2:22 fullerene either in

natural resources in space and on the Earth or in artificially synthesized materials, electronic, optical and biomedical devices, polymers, composites, catalysts, nanowires, batteries, sensors, optical limiters, solar

ophotonic lenses with improved optical absorption characteristics, refraction features and wettability, diagnostic and therapeutic agents, pharmaceutical substances, such as for diabetes, targeted

:22, IR spectroscopy, molar absorptivity, integrated molar absorptivity

The authors are grateful to the Ministry of Education, Science and Technological Development of the f Serbia and to the University of Belgrade for financial support of this research (project III 45009).

20

Chemical and Process Engineering


ASYMPTOTIC STABILITY

OF SINGULAR TIME DEL

LYAPUNOV’S APPROACH

BASED ON JENSEN’S ANIvan M. Buzurovic1, Dragutin

1Division of Medical Physics and Biophysics, Harvard Medical School, Boston MA, USA2Megatrend University, Faculty of Civil Aviation,

3University of Belgrade, Faculty of Mechanical Engineering, 11000 Belgrade, Serbia4University of Belgrade, Innovation Centre


Abstract

In this paper, the asymptotic of linear continuous singular timeLyapunov-like function and Jensen’s and Coppel’s inequality, a asymptoticof algebraic inequalities. In that sense tto singular time-delay systems and some conditions have been derived using two approach based on the classical aggregation functions defined on the space of consistent initial conditions: classical and LMI approach. The first approach is based on the algebraic matrix transformations, while the second approach uses the linear matrix inequalities. LMI approach providesadditional restriction on the state vector.it has been showed that the numerical computation is reduced. effectiveness of the proposed approaches.

Keywords

Singular linear time delay systems, Asymptotic stability, Subset of consistent initial conditions, LMI methods.

Acknowledgement

This research was partially supported by the Ministry of Sciences and TechMathematical Institute SANU Belgrade Grantstructures - Mechanics of materials’



Zlatibor, July 0


ASYMPTOTIC STABILITY

OF SINGULAR TIME DELAY SYSTEMS:

LYAPUNOV’S APPROACH

BASED ON JENSEN’S AND COPPEL’S INEQUALIT, Dragutin Lj. Debeljkovic2*, Darko M. Radojevic3, Goran V. Simeunovic

Division of Medical Physics and Biophysics, Harvard Medical School, Boston MA, USA

Megatrend University, Faculty of Civil Aviation, Marshal Tolbuhin Boulevard 8, 11000 Belgrade


University of Belgrade, Innovation Centre of Faculty of Mechanical Engineering, 11000 Belgrade, Serbia


In this paper, the asymptotic of linear continuous singular time-delay systems is studied. By using suitable like function and Jensen’s and Coppel’s inequality, a asymptotic condition is derived as a set

of algebraic inequalities. In that sense the concept of simultaneous stability and attractivenessdelay systems and some conditions have been derived using two approach based on the

gregation functions defined on the space of consistent initial conditions: classical and LMI approach. The first approach is based on the algebraic matrix transformations, while the second approach uses the linear matrix inequalities. LMI approach provides a simple numerical solution and does not impose additional restriction on the state vector. The comparison of this method with some previous one is done and it has been showed that the numerical computation is reduced. Numerical example is given to show teffectiveness of the proposed approaches.


This research was partially supported by the Ministry of Sciences and Technology of Republic of Serbia Mathematical Institute SANU Belgrade Grant OI 174001: ‘Dynamics of hybrid systems with complex

University of Belgrade, School of Mechanical Engineering.

21





AY SYSTEMS:

D COPPEL’S INEQUALITY , Goran V. Simeunovic4





[email protected]

delay systems is studied. By using suitable condition is derived as a set

attractiveness is extended delay systems and some conditions have been derived using two approach based on the

gregation functions defined on the space of consistent initial conditions: classical and LMI approach. The first approach is based on the algebraic matrix transformations, while the second approach

a simple numerical solution and does not impose The comparison of this method with some previous one is done and

Numerical example is given to show the


nology of Republic of Serbia - OI 174001: ‘Dynamics of hybrid systems with complex



LYAPUNOV STABILITY

OF DISCRETE DESCRIPTOR DELAYED S

APPROACH BASED ON

CONVOLUTION AND JENSIvan M. Buzurovic1, Dragutin Lj. Debeljkovic

1Division of Medical Physics and Biophysics, Harvard Medical School, Boston MA2Megatrend University, Faculty of Civil Aviation,

3High School of Professional Studies, 12000 Pozarevac, Serbia4University of Belgrade, Innovation Centre


Abstract

In this paper, the asymptotic of linear discrete descriptortimeLyapunov function defined on the subspace of consistent initial conditions, discrete form of convolution integral and Jensen’s inequality, a asymptotic condition is derived as a set of algebraic inequalities. In that sense the concept of asymptoticis extended to dishave been derived using two approach based on the classical aggregation functions defined on the space of consistent initial conditions: classical and LMI approach. The first approach is based on the transformations and discrete version of convolution integral, while the second approach uses the linear matrix inequalities. LMI approach provides a simple numerical solution and does not impose additional restriction on the state vector. In both cases only sufficient conditions were derived. method with some previous one is done and it has been showed that the numerical computation is less complicated.

Keywords

Discrete descriptor time delay systems, Asymptotic stabiLMI approach.

Acknowledgement

This research was partially supported by the Ministry of Sciences and Technology of Republic of Serbia Mathematical Institute SANU Belgrade Grantstructures - Mechanics of materials’



Zlatibor, July 0


LYAPUNOV STABILITY

DESCRIPTOR DELAYED S

APPROACH BASED ON

CONVOLUTION AND JENSEN’S INEQUALITYLj. Debeljkovic2*, Aleksandra M. Jovanovic3, Goran V. Simeunovic

Division of Medical Physics and Biophysics, Harvard Medical School, Boston MA

Megatrend University, Faculty of Civil Aviation, Marshal Tolbuhin Boulevard 8, 11000 Belgrade

High School of Professional Studies, 12000 Pozarevac, Serbia

University of Belgrade, Innovation Centre of Faculty of Mechanical Engineering,11000


In this paper, the asymptotic of linear discrete descriptortime-delay systems is studied. By using suitable unction defined on the subspace of consistent initial conditions, discrete form of convolution

integral and Jensen’s inequality, a asymptotic condition is derived as a set of algebraic inequalities. In that he concept of asymptoticis extended to discrete descriptor time-delay systems and some conditions

have been derived using two approach based on the classical aggregation functions defined on the space of consistent initial conditions: classical and LMI approach. The first approach is based on the transformations and discrete version of convolution integral, while the second approach uses the linear matrix inequalities. LMI approach provides a simple numerical solution and does not impose additional

In both cases only sufficient conditions were derived. method with some previous one is done and it has been showed that the numerical computation is less

Discrete descriptor time delay systems, Asymptotic stability, Subset of consistent initial conditions,

This research was partially supported by the Ministry of Sciences and Technology of Republic of Serbia Mathematical Institute SANU Belgrade Grant OI 174001: ‘Dynamics of hybrid


22





DESCRIPTOR DELAYED SYSTEMS:

EN’S INEQUALITY , Goran V. Simeunovic4


, 11000 Belgrade, Serbia

High School of Professional Studies, 12000 Pozarevac, Serbia

of Faculty of Mechanical Engineering,11000 Belgrade, Serbia

[email protected]

delay systems is studied. By using suitable unction defined on the subspace of consistent initial conditions, discrete form of convolution

integral and Jensen’s inequality, a asymptotic condition is derived as a set of algebraic inequalities. In that delay systems and some conditions

have been derived using two approach based on the classical aggregation functions defined on the space of consistent initial conditions: classical and LMI approach. The first approach is based on the algebraic matrix transformations and discrete version of convolution integral, while the second approach uses the linear matrix inequalities. LMI approach provides a simple numerical solution and does not impose additional

In both cases only sufficient conditions were derived. The comparison of this method with some previous one is done and it has been showed that the numerical computation is less

lity, Subset of consistent initial conditions,

This research was partially supported by the Ministry of Sciences and Technology of Republic of Serbia - systems with complex



PHASE CHANGE BIODEGR

BASED ON ORGANICALLY

AND WASTE FATTY ACIDMilena S. Stojiljkovic1, Stanisa

1 University of Nis, Faculty of Technology, Bulevar2 CIS Institute, Vojislava


Abstract

Phase change materials (PCMs) are gaining more interest in systems of saving and rational disposal of energy in buildings, air conditioning, agriculture, industry, medicine, etc.In this paper, the mixtures that were analysed for thermal energy storage are also having biodegradable properties. The mixturescomponents are organically modified clay, paraffin and waste Glycerol). MONG contain a mixture of fatty acid methyl esters, ethyl esters, free fatty acids and glycerides. Paraffin mixtures have a higher evaporation pressure of most esters, making them more susceptible to weight loss and changes in physical properties due to evaporation. Esters are more stable mixtures that do not lose weight during heating. In this paper, the samples cooling process at isolated conditions lasting up to 8 hours was examined. The starting temperature was 80°C. A mixture of MONG, modified clay and paraffin in a mass ratio of 1: 1: 1 proved to be more favourable while after 3 hours the temperature dropped to 40°C. The combination of MONG and modified clay at mass ratio 1:dropped to 40°C after 2 hours. The FTIR bands indicatedThe combination of paraffin, MONG and organically modified clays has slower cooling but also slight discontinuity during cooling, while MONG, in combination with organically modified clay, cools faster but gives a continuous flow of cooling without singularity. The economically more effective mass ratio of MONGs and organically modified clays is 2: 1. This combination is suitabshapes for application in industry, construction, agriculture and medicine. The advantage of this combination is biodegradability and low price of MONG and organically modified clay.

Keywords

Phase change materials; Thermal energy storage; MONG; Organically modified clay; Biodegradable mixture

Acknowledgement

This work was supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia under Project NoIII 42006.



Zlatibor, July 0


PHASE CHANGE BIODEGRADABLE MATERIALS

BASED ON ORGANICALLY MODIFIED CLAY, PARAF

AND WASTE FATTY ACID (MONG)tanisa T. Stojiljkovic1, Bratislav Z. Todorovic1, Mirjana M. Reljic

University of Nis, Faculty of Technology, Bulevar Oslobodjenja 124, 16000 Leskovac, Serbia

Institute, Vojislava Ilića 88, Belgrade, Serbia


Phase change materials (PCMs) are gaining more interest in systems of saving and rational disposal of onditioning, agriculture, industry, medicine, etc.In this paper, the mixtures that were

for thermal energy storage are also having biodegradable properties. The mixturescomponents are organically modified clay, paraffin and waste glycerine distillation resin (MONGGlycerol). MONG contain a mixture of fatty acid methyl esters, ethyl esters, free fatty acids and glycerides. Paraffin mixtures have a higher evaporation pressure of most esters, making them more susceptible to

physical properties due to evaporation. Esters are more stable mixtures that do

In this paper, the samples cooling process at isolated conditions lasting up to 8 hours was examined. The re was 80°C. A mixture of MONG, modified clay and paraffin in a mass ratio of 1: 1: 1

while after 3 hours the temperature dropped to 40°C. The combination of modified clay at mass ratio 1:1 and pure MONG is more unfavourable because the temperature

The FTIR bands indicated the presence of appropriate chemical groups.The combination of paraffin, MONG and organically modified clays has slower cooling but also slight

ling, while MONG, in combination with organically modified clay, cools faster but gives a continuous flow of cooling without singularity. The economically more effective mass ratio of MONGs and organically modified clays is 2: 1. This combination is suitable for encapsulation in appropriate geometric shapes for application in industry, construction, agriculture and medicine. The advantage of this combination is biodegradability and low price of MONG and organically modified clay.

ials; Thermal energy storage; MONG; Organically modified clay; Biodegradable mixture

This work was supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia under Project NoIII 42006.

23





ADABLE MATERIALS

MODIFIED CLAY, PARAFFIN

(MONG) , Mirjana M. Reljic2

Oslobodjenja 124, 16000 Leskovac, Serbia

Phase change materials (PCMs) are gaining more interest in systems of saving and rational disposal of onditioning, agriculture, industry, medicine, etc.In this paper, the mixtures that were

for thermal energy storage are also having biodegradable properties. The mixturescomponents are ation resin (MONG- Matter Organic Non-

Glycerol). MONG contain a mixture of fatty acid methyl esters, ethyl esters, free fatty acids and glycerides. Paraffin mixtures have a higher evaporation pressure of most esters, making them more susceptible to

physical properties due to evaporation. Esters are more stable mixtures that do

In this paper, the samples cooling process at isolated conditions lasting up to 8 hours was examined. The re was 80°C. A mixture of MONG, modified clay and paraffin in a mass ratio of 1: 1: 1

while after 3 hours the temperature dropped to 40°C. The combination of because the temperature

the presence of appropriate chemical groups. The combination of paraffin, MONG and organically modified clays has slower cooling but also slight

ling, while MONG, in combination with organically modified clay, cools faster but gives a continuous flow of cooling without singularity. The economically more effective mass ratio of MONGs

le for encapsulation in appropriate geometric shapes for application in industry, construction, agriculture and medicine. The advantage of this combination

ials; Thermal energy storage; MONG; Organically modified clay; Biodegradable mixture

This work was supported by the Ministry of Education, Science and Technological Development of the


Invited lecture

POSSIBILITY FOR REMO

THERMAL DEGRADATION

NATURAL ALUMINOSILICSanja Dobrnjac1*, Mirko Dobrnjac

1Projekt JSC, 78000 Banjalu2University of Banjaluka, Faculty of Mechanical Engineering, Department of Thermotechnics, 78000

3University of Banjaluka, Faculty of Natural Sciences and Mathematics, 78000 Banjaluka, Bosnia and

4University of East Sarajevo, Faculty of Technology, 75400 Zvornik, Bosnia and Herzegovina5Institute of General and Physical Chemistry, Belgrade, Serbia


Abstract

Everyday food preparation often involves cooking on vegetable oil, where heating at temperatures over 110°C changes the quality of oil due to various chemical reactions. In this paper, the degree of thermal degradation of edible oil was investigat10 and 30 minutes. The reference to the quality of edible oil is the content of free fatty acids (FFA) which increases as the temperature rises, due to hydrolysis.By removing the thermal degradation products of the edible oil used, it would be possible to prolong the time of use of the oil for other useful purposes, and thus its final disposal as waste, would be postponed, which is in accordance with environmental protection requirements. IFFA on natural aluminosilicates was investigated. The results obtained show a decrease in FFA content of 72 to 80 %, depending on the time of warming and the type of adsorbent used.Further research should be continued on the regeneration of used edible oil by testing other quality parameters, as well as the application of other adsorbents.

Keywords

Edible oil, thermal degradation, free fatty



Zlatibor, July 0


POSSIBILITY FOR REMOVING PRODUCTS OF

THERMAL DEGRADATION OF EDIBLE OIL BY

NATURAL ALUMINOSILICATES, Mirko Dobrnjac2, Jelena Penavin Skundric3, Ljubica Vasiljevic

Blagojevic5, Zvjezdana Sandic3

Projekt JSC, 78000 Banjaluka, Bosnia and Herzegovina

University of Banjaluka, Faculty of Mechanical Engineering, Department of Thermotechnics, 78000 Banjaluka, Bosnia and Herzegovina

University of Banjaluka, Faculty of Natural Sciences and Mathematics, 78000 Banjaluka, Bosnia andHerzegovina

University of East Sarajevo, Faculty of Technology, 75400 Zvornik, Bosnia and Herzegovina

Institute of General and Physical Chemistry, Belgrade, Serbia


Everyday food preparation often involves cooking on vegetable oil, where heating at temperatures over 110°C changes the quality of oil due to various chemical reactions. In this paper, the degree of thermal degradation of edible oil was investigated when heating oil at a temperature ranging from 110 to 190°C for 10 and 30 minutes. The reference to the quality of edible oil is the content of free fatty acids (FFA) which increases as the temperature rises, due to hydrolysis.

egradation products of the edible oil used, it would be possible to prolong the time of use of the oil for other useful purposes, and thus its final disposal as waste, would be postponed, which is in accordance with environmental protection requirements. In line with this, the possibility of adsorption of

on natural aluminosilicates was investigated. The results obtained show a decrease in FFA content of %, depending on the time of warming and the type of adsorbent used.

be continued on the regeneration of used edible oil by testing other quality parameters, as well as the application of other adsorbents.

free fatty acids (FFA), adsorption

24





VING PRODUCTS OF

OF EDIBLE OIL BY

ATES , Ljubica Vasiljevic4, Stevan

University of Banjaluka, Faculty of Mechanical Engineering, Department of Thermotechnics, 78000

University of Banjaluka, Faculty of Natural Sciences and Mathematics, 78000 Banjaluka, Bosnia and

University of East Sarajevo, Faculty of Technology, 75400 Zvornik, Bosnia and Herzegovina

Institute of General and Physical Chemistry, Belgrade, Serbia

Everyday food preparation often involves cooking on vegetable oil, where heating at temperatures over 110°C changes the quality of oil due to various chemical reactions. In this paper, the degree of thermal

ed when heating oil at a temperature ranging from 110 to 190°C for 10 and 30 minutes. The reference to the quality of edible oil is the content of free fatty acids (FFA) which

egradation products of the edible oil used, it would be possible to prolong the time of use of the oil for other useful purposes, and thus its final disposal as waste, would be postponed, which is

n line with this, the possibility of adsorption of on natural aluminosilicates was investigated. The results obtained show a decrease in FFA content of

be continued on the regeneration of used edible oil by testing other quality


Invited lecture

APPLICATION OF 3D DI

METHOD IN PROCESS EN

1University of Belgrade, Faculty of Mechanical Engineering, Department of Process Engineering and Environmental Protection,


Abstract

Process engineering encompasses diverse industrial fields, such as chemical, petrochemical, pharmaceutical, biotechnological etc., and pressure equipment is an indispensabplants. Due to wide range of applications, pressure equipment comes in different shapes, from simple to very complex, and can be subjected to different loadings in its working life (static, dynamic, thermal etc.) so the knowledge of mechanical behaviour is of great importance. This paper presents several examples of application of 3D Digital Image Correlation method (3Dgeometrically complex structures. A 3D Digital Image Correlation overcomes the limitations of conventional methods and enables fullmeasurement. Aramis system was used for the experimental analysis. Welded joint standardized specimen is used as an example for simple shaped object. For geometrically complex structure, several examples are used: globe valve housing with distinctive sphere/cylinder intersection, cylindrical horizontal pressure vessel with cylindrical nozzles and T joint pipe. Experimental resultadequate for solving geometrically complex problems and provides an opportunity for further development and improvement for practical industrial application.

Keywords

3D Digital Image Correlation method; von Mises stjoints;

Acknowledgement

This research was supported by Ministry of Education, Science and Technological Development of Republic of Serbia under Projects TR35031 and TR35040.



Zlatibor, July 0


APPLICATION OF 3D DIGITAL IMAGE CORRELATI

METHOD IN PROCESS ENGINEERINGNenad Mitrovic1

University of Belgrade, Faculty of Mechanical Engineering, Department of Process Engineering and Environmental Protection, Kraljice Marije 16,11000 Belgrade, Serbia


Process engineering encompasses diverse industrial fields, such as chemical, petrochemical, pharmaceutical, biotechnological etc., and pressure equipment is an indispensable part of every industrial plants. Due to wide range of applications, pressure equipment comes in different shapes, from simple to very complex, and can be subjected to different loadings in its working life (static, dynamic, thermal etc.) so the

e of mechanical behaviour is of great importance. This paper presents several examples of application of 3D Digital Image Correlation method (3D-DIC)for simple shaped objects, as well as for geometrically complex structures. A 3D Digital Image Correlation method is an optical method that overcomes the limitations of conventional methods and enables full-field displacement and strain measurement. Aramis system was used for the experimental analysis. Welded joint standardized specimen

r simple shaped object. For geometrically complex structure, several examples are used: globe valve housing with distinctive sphere/cylinder intersection, cylindrical horizontal pressure vessel with cylindrical nozzles and T joint pipe. Experimental results demonstrate that the 3Dadequate for solving geometrically complex problems and provides an opportunity for further development and improvement for practical industrial application.

3D Digital Image Correlation method; von Mises strain; Process Engineering; pressure equipment; welded

This research was supported by Ministry of Education, Science and Technological Development of Republic of Serbia under Projects TR35031 and TR35040.

25





ITAL IMAGE CORRELATION

GINEERING

University of Belgrade, Faculty of Mechanical Engineering, Department of Process Engineering and Marije 16,11000 Belgrade, Serbia

Process engineering encompasses diverse industrial fields, such as chemical, petrochemical, le part of every industrial

plants. Due to wide range of applications, pressure equipment comes in different shapes, from simple to very complex, and can be subjected to different loadings in its working life (static, dynamic, thermal etc.) so the

e of mechanical behaviour is of great importance. This paper presents several examples of DIC)for simple shaped objects, as well as for

method is an optical method that field displacement and strain

measurement. Aramis system was used for the experimental analysis. Welded joint standardized specimen r simple shaped object. For geometrically complex structure, several examples are

used: globe valve housing with distinctive sphere/cylinder intersection, cylindrical horizontal pressure vessel s demonstrate that the 3D-DIC method is

adequate for solving geometrically complex problems and provides an opportunity for further development

Process Engineering; pressure equipment; welded



TGA-DSC-MS ANALYSIS OF PY

VARIOUS BIOMASSES WI

(MODELNebojsa Manic1,* ; Bojan Jankovic

1University of Belgrade, Faculty of Mechanical Engineering, Fuel and Combustio

Kraljice Marije 16, P.O. Box 35, 11120 Belgrade, Serbia2University of Belgrade, Faculty of Physical Chemistry, Department of General and Physical Chemistry,

Studentski trg 123University of Belgrade, Faculty of Mechanical Engineering, Department for Process Engineering and

Environmental protection, Kraljice


Abstract

Pyrolysis process of three different solid biomass samples (hazelnut shell (HS), sawdust (Beech), and sawdust chemically treated (SDCT)) were mass spectrometry (MS). Thermal decomposition of tpyrolysis process was identified as removal of water, devolatilization, and formation of biobehaviour of the samples shows the distinctions during the decompositionthe sample structure. Regarding to pyrolysis were identified as H2, CHcharacterization and analysis, it was shown that (HSpyrolysis at high temperature, a more gaseous products compared to other systems, are very favoured. Kinetic analysis based on obtained experimental data were performed with Isoconversional (modelmethod in order to determine variation magnitudes of effective activation energy (Ea) values on conversion fraction (α) during pyrolysis. The variations of Ea with α arise from the different chemical structures among cellulose, hemicelluloses and lignin in tested samples that may

Keywords

Biomass, Volatilization, Model-free, Pyrolysis mechanisms,

Acknowledgement

Authors would like to acknowledge financial support of Ministry of EducationDevelopment of the Republic of Serbia under the Projects III42010 and 172015.



Zlatibor, July 0


MS ANALYSIS OF PYROLYSIS PROCESS OF

VARIOUS BIOMASSES WITH ISOCONVERSIONAL

(MODEL-FREE) KINETICS ; Bojan Jankovic2; Dragoslava Stojiljkovic1; Vladimir Jovanovic

University of Belgrade, Faculty of Mechanical Engineering, Fuel and Combustio

Marije 16, P.O. Box 35, 11120 Belgrade, Serbia

University of Belgrade, Faculty of Physical Chemistry, Department of General and Physical Chemistry, trg 12-16, P. O. Box 137, 11001 Belgrade, Serbia

, Faculty of Mechanical Engineering, Department for Process Engineering and Environmental protection, Kraljice Marije 16, P.O. Box 35, 11120 Belgrade, Serbia


Pyrolysis process of three different solid biomass samples (hazelnut shell (HS), sawdust (Beech), and sawdust chemically treated (SDCT)) were analysed by simultaneous thermal analysis (STA), coupled with mass spectrometry (MS). Thermal decomposition of these samples was performedand three stages of the pyrolysis process was identified as removal of water, devolatilization, and formation of bio

of the samples shows the distinctions during the decomposition process mass spectrometry analysis the main gaseous products released during

, CH4, H2O, CO2 (C3H8), CO, and C2H6. According to performed characterization and analysis, it was shown that (HS) could be a good combustion fuel, since that during its pyrolysis at high temperature, a more gaseous products compared to other systems, are very favoured. Kinetic analysis based on obtained experimental data were performed with Isoconversional (modelmethod in order to determine variation magnitudes of effective activation energy (Ea) values on conversion fraction (α) during pyrolysis. The variations of Ea with α arise from the different chemical structures among

n in tested samples that may affect their effective activation energies.

free, Pyrolysis mechanisms, Devolatilization index

Authors would like to acknowledge financial support of Ministry of Education, Science and Technological Development of the Republic of Serbia under the Projects III42010 and 172015.

26





ROLYSIS PROCESS OF

TH ISOCONVERSIONAL

; Vladimir Jovanovic1; Martina Balac3

University of Belgrade, Faculty of Mechanical Engineering, Fuel and Combustion Laboratory,

University of Belgrade, Faculty of Physical Chemistry, Department of General and Physical Chemistry, 16, P. O. Box 137, 11001 Belgrade, Serbia

, Faculty of Mechanical Engineering, Department for Process Engineering and Marije 16, P.O. Box 35, 11120 Belgrade, Serbia

Pyrolysis process of three different solid biomass samples (hazelnut shell (HS), sawdust (Beech), and by simultaneous thermal analysis (STA), coupled with hese samples was performedand three stages of the

pyrolysis process was identified as removal of water, devolatilization, and formation of bio-char. Thermal related to differences in

mass spectrometry analysis the main gaseous products released during . According to performed

) could be a good combustion fuel, since that during its pyrolysis at high temperature, a more gaseous products compared to other systems, are very favoured. Kinetic analysis based on obtained experimental data were performed with Isoconversional (model-free) method in order to determine variation magnitudes of effective activation energy (Ea) values on conversion fraction (α) during pyrolysis. The variations of Ea with α arise from the different chemical structures among

their effective activation energies.

, Science and Technological


MATHEMATICAL

ANALYSIS OF A SMALL

POWER SYSTEM BASED O

DOWNDRAFT GASIFICATIMarta Trninic1, Dusan Todorovi

Skreiberg1University of Belgrade, Faculty of Mechanical Engineering, Fuel and Combustion Laboratory,

Kraljice Marije 16, P.O. Box 35, 11120 Be2SINTEF Energy Research, Trondheim, Norway


Abstract

The paper presents a simple mathematical model for designing, optimizing and simulating smallCHP scale plant with use of biomass waste downdraft gasification. A downdraft gasifier has been used as the starting point in the study, due to its low tar content and effective way of using heat in the engine’s exhaust gases to dry and pyrolyze thwater from the cooling circuit of the engine and from producer gas cooling is directly used for the district heating network, air or steam preheating. The mathematical model includes modelled components as a downdraft engine using the characteristic equation approach method.The mathematical model enables the outputs of the plant to be evaluated and calculated for different types of biomass and operating conditions. The results demonstraperformance of CHP plants using several types of biomass waste and enables comparisons to be made between operating conditions for real applications.

Keywords

Biomass, downdraft gasification, CHP



Zlatibor, July 0


MATHEMATICAL MODELLING AND PERFOR

ANALYSIS OF A SMALL-SCALE COMBINED HEAT

POWER SYSTEM BASED ON BIOMASS WASTE

DOWNDRAFT GASIFICATION an Todorovic1, Aleksandar Jovovic1, Dragoslava Stojiljkovi

Skreiberg2, Liang Wang2, Nebojsa Manic1


Marije 16, P.O. Box 35, 11120 Belgrade, Serbia

SINTEF Energy Research, Trondheim, Norway


The paper presents a simple mathematical model for designing, optimizing and simulating smallCHP scale plant with use of biomass waste downdraft gasification. A downdraft gasifier has been used as the starting point in the study, due to its low tar content and effective way of using heat in the engine’s exhaust gases to dry and pyrolyze the different solid biomass waste. Hot water from the cooling circuit of the engine and from producer gas cooling is directly used for the district heating network, air or steam preheating. The mathematical model includes modelled components as a downdraft gasifier, an internal combustion engine using the characteristic equation approach method. The mathematical model enables the outputs of the plant to be evaluated and calculated for different types of biomass and operating conditions. The results demonstrate that it is a useful tool for assessing the performance of CHP plants using several types of biomass waste and enables comparisons to be made between operating conditions for real applications.

Biomass, downdraft gasification, CHP

27





MODELLING AND PERFORMANCE

SCALE COMBINED HEAT AND

N BIOMASS WASTE

, Dragoslava Stojiljkovic1, Øyvind


The paper presents a simple mathematical model for designing, optimizing and simulating small–medium

A downdraft gasifier has been used as the starting point in the study, due to its low tar content and effective e different solid biomass waste. Hot

water from the cooling circuit of the engine and from producer gas cooling is directly used for the district

gasifier, an internal combustion

The mathematical model enables the outputs of the plant to be evaluated and calculated for different types of te that it is a useful tool for assessing the

performance of CHP plants using several types of biomass waste and enables comparisons to be made

28

Experimental Techniques


RESEARCH OF LEAN PRE

CHEMILUMINESCENCE TOVuk Adžic1, Mustafa Makhzoum

1University of Belgrade, Faculty of Mechanical Engineering, Fuel and Combustion Laboratory, 11000





Abstract

Investigation of combustion of lean premixed flame in a swirl combustor is performed numerically and experimentally. The flame structure was monitored using chemically reacting turbulent flow with strong swirl and shear is flame are acquired and the flame structure investigated, particularly looking for the position of flame front. The position of flame front, which is the area with highest exothermic chemical reactions, is deduced from acquired images. To identify the zone of flame front on the basis of two dimensional image of flame, which is actually three dimensional, the method of image tomography is applied. The tomography of the acquired images is numerically performed using the Abel transfois used to get tomograms. The obtained tomograms enable precise positioning of the flame front and confirm the validity of results of numerical investigation of swirl combustion.

Keywords

Premixed Flame, Swirl Combustor, Chemiluminescence, Tomography, Abel Transform.



Zlatibor, July 0


RESEARCH OF LEAN PREMIXED COMBUSTOR BY

CHEMILUMINESCENCE TOMOGRAPHY, Mustafa Makhzoum2, Aleksandar Milivojevic3 and Miroljub Adžic

University of Belgrade, Faculty of Mechanical Engineering, Fuel and Combustion Laboratory, 11000Belgrade, Serbia

University of Belgrade, Faculty of Mechanical Engineering, Fuel and Combustion Laboratory, 11000 Belgrade, Serbia, PhD Student

University of Belgrade, Faculty of Mechanical Engineering, Fuel and Combustion Laboratory, 11000 Belgrade, Serbia

University of Belgrade, Faculty of Mechanical Engineering, Fuel and Combustion Laboratory, 11000 Belgrade, Serbia


ion of lean premixed flame in a swirl combustor is performed numerically and experimentally. The flame structure was monitored using CH* chemiluminescence imaging. The complex chemically reacting turbulent flow with strong swirl and shear is analysed. The images of axially symmetric flame are acquired and the flame structure investigated, particularly looking for the position of flame front. The position of flame front, which is the area with highest exothermic chemical reactions, is deduced from

mages. To identify the zone of flame front on the basis of two dimensional image of flame, which is actually three dimensional, the method of image tomography is applied. The tomography of the acquired images is numerically performed using the Abel transform. The in-house developed numerical Abel transform is used to get tomograms. The obtained tomograms enable precise positioning of the flame front and confirm the validity of results of numerical investigation of swirl combustion.

Swirl Combustor, Chemiluminescence, Tomography, Abel Transform.

29

ence of Experimental and




MIXED COMBUSTOR BY

MOGRAPHY and Miroljub Adžic4

University of Belgrade, Faculty of Mechanical Engineering, Fuel and Combustion Laboratory, 11000




ion of lean premixed flame in a swirl combustor is performed numerically and CH* chemiluminescence imaging. The complex

images of axially symmetric flame are acquired and the flame structure investigated, particularly looking for the position of flame front. The position of flame front, which is the area with highest exothermic chemical reactions, is deduced from

mages. To identify the zone of flame front on the basis of two dimensional image of flame, which is actually three dimensional, the method of image tomography is applied. The tomography of the acquired

house developed numerical Abel transform is used to get tomograms. The obtained tomograms enable precise positioning of the flame front and confirm

Swirl Combustor, Chemiluminescence, Tomography, Abel Transform.


BIOMECHANICAL BEHAVI

CEMENTMAXCEM ELITEAleksandra Mitrovic*1, Nenad Mitrovic

*1University of Belgrade, Faculty of Te2University of Belgrade, Faculty of Mechanical Engineering, Kraljice

3University of Belgrade, Vinca Institute, Mike Petrovića4Innovation Center of Faculty of Mechanical Engineering, Kraljice


Abstract

Resin based cements (RBCs) have become very popular in dental practice for cementation of dental restorations, especially considering allmajor concerns for the clinical performance of i.e.strainthat accompanies the chainproduce a considerable amount of heat, due to the light enreaction of polymerization. The purpose of this study was to determine the temperature changes during the photothermocouples and to measure strain field of the selfOrange, CA, USA) using 3D optical system Aramis 2M (GOM, Braunschweig, Germany) based on Digital Image Correlation method. Three ø5×2 mm sized and three ø5×1 mm samples of Maxcem Elite were prepared by filling teflon ring-type polymerization of the samples with a LEDAll measurements were performed at room temperature. showed that peripheral zone of the samples had the highest strain values in both groups. All the results were material-dependent and probably correlated to the composition of each material, which is not fully disclosed by the manufacturers.

Key words

Resin based cement, Maxcem Elite, thermocouples, strain, 3D Digital Image Correlation

Acknowledgement

The authors are grateful to Neodent (Belgrade, Serbia) for providing the material used in this study. This research was supported by Ministry of EducaSerbia under Projects TR35031 and TR35040.



Zlatibor, July 0


BIOMECHANICAL BEHAVIOR OF RESIN BASED

CEMENTMAXCEM ELITE , Nenad Mitrovic2, Dejana Popovic3, Milos Milosevic4, Dusan Antonovic



University of Belgrade, Vinca Institute, Mike Petrovića Alasa 12-14, Belgrade, Serbia

Innovation Center of Faculty of Mechanical Engineering, Kraljice Marije 16, Belgrade, Serbia


have become very popular in dental practice for cementation of dental restorations, especially considering all-ceramics, due to improved adhesion features. However, one of the

or concerns for the clinical performance of resin based cements is the polymerization that accompanies the chain-growth polymerization of dimethacrylate monomers

produce a considerable amount of heat, due to the light energy from the curing lights and exothermic

The purpose of this study was to determine the temperature changes during the photothermocouples and to measure strain field of the self-etching, self-adhesive RBC

3D optical system Aramis 2M (GOM, Braunschweig, Germany) based on Digital Image Correlation method. Three ø5×2 mm sized and three ø5×1 mm samples of Maxcem Elite were

type moulds. Digital images were recorded immediately after photopolymerization of the samples with a LED-curing unit for 20 s, according to manufacturer’s recommendation.All measurements were performed at room temperature. Temperature curves indicated similar patteshowed that peripheral zone of the samples had the highest strain values in both groups. All the results were

dependent and probably correlated to the composition of each material, which is not fully disclosed

Maxcem Elite, thermocouples, strain, 3D Digital Image Correlation

The authors are grateful to Neodent (Belgrade, Serbia) for providing the material used in this study. This research was supported by Ministry of Education, Science and Technological Development of Republic of Serbia under Projects TR35031 and TR35040.

30





OR OF RESIN BASED

, Dusan Antonovic1

chnology and Metallurgy, Karnegijeva 4, Belgrade, Serbia


14, Belgrade, Serbia


[email protected]

have become very popular in dental practice for cementation of dental ceramics, due to improved adhesion features. However, one of the

the polymerization shrinkage growth polymerization of dimethacrylate monomers. Also, RBCs can

ergy from the curing lights and exothermic

The purpose of this study was to determine the temperature changes during the photo-polymerization using adhesive RBC, Maxcem Elite (Kerr,

3D optical system Aramis 2M (GOM, Braunschweig, Germany) based on Digital Image Correlation method. Three ø5×2 mm sized and three ø5×1 mm samples of Maxcem Elite were

Digital images were recorded immediately after photo-curing unit for 20 s, according to manufacturer’s recommendation.

Temperature curves indicated similar patterns. DIC showed that peripheral zone of the samples had the highest strain values in both groups. All the results were

dependent and probably correlated to the composition of each material, which is not fully disclosed

Maxcem Elite, thermocouples, strain, 3D Digital Image Correlation

The authors are grateful to Neodent (Belgrade, Serbia) for providing the material used in this study. This tion, Science and Technological Development of Republic of


IMPACT OF DENSITY OF

ABSORPTION POWER OF Jovan D. Tanaskovic1*, Aleksandra D. Mitrovic

1University of Belgrade, Faculty of Mechanical Engineering, Department of Rail Vehicles, 11000 Belgrade,

2Technical College, 152а Bulevar3Newcastle University, Newcastle upon Tyne, NE1 7RU, UK


Abstract

Safety of railway vehicles is one of the most importance steps in developing and design of them. Passive safety elements have a role to reduce consequeenergy. Applying a proper standard and adequate design of railway vehicle structure has a direct impact on safety of railway traffic. One of many ways for collision energy absorption is the tubeworks on the principle of shrinking the foam filled tube passing through special cone bushing. Fill made from high density polyurethane has a role to increase deformation resistance during elasticthe tube. Seamless tube was made from low carbon steel while the cone bushing was made from quench and tempered carbon steel. This type of absorber is designed to install in a line (behind) with standard buffer. Using this type of absorber energy absorption occurs by ebetween the tube and cone bushing and pressing of the foam. With the aim to show influence of the density of the foam on absorption power, experimental investigations of tubes filled by polyurethane foam of density were done. Results of experimental investigations show that increase of density gives higher deformation resistance as well as higher absorption power. Further investigations will be directed to improve of absorption characteristics by chose a most acceptable density of foam.

Keywords

Railway Safety, Passive Safety, Foam Filled Seamless Tube, Experimental Investigations, Polyurethane Foam

Acknowledgement

The research work is funded by the Ministry of Education, Science and Technological DeRepublic of Serbia, Projects TR35045 and TR35031.



Zlatibor, July 0


IMPACT OF DENSITY OF POLYURETHANE FOAM ON

ABSORPTION POWER OF ENERGY ABSORBER, Aleksandra D. Mitrovic2, Francis J. Franklin3, Dra

University of Belgrade, Faculty of Mechanical Engineering, Department of Rail Vehicles, 11000 Belgrade, Serbia

Technical College, 152а Bulevar Zorana Đinđića, Belgrade, Serbia

Newcastle University, Newcastle upon Tyne, NE1 7RU, UK

esponding author e-mail: [email protected]

Safety of railway vehicles is one of the most importance steps in developing and design of them. Passive safety elements have a role to reduce consequences of collision to a minimal by absorbing collision kinetic energy. Applying a proper standard and adequate design of railway vehicle structure has a direct impact on safety of railway traffic. One of many ways for collision energy absorption is the tubeworks on the principle of shrinking the foam filled tube passing through special cone bushing. Fill made from high density polyurethane has a role to increase deformation resistance during elastic

mless tube was made from low carbon steel while the cone bushing was made from quench and tempered carbon steel. This type of absorber is designed to install in a line (behind) with standard buffer. Using this type of absorber energy absorption occurs by elastic-plastic deformation of the tube, friction between the tube and cone bushing and pressing of the foam. With the aim to show influence of the density of the foam on absorption power, experimental investigations of tubes filled by polyurethane foam of density were done. Results of experimental investigations show that increase of density gives higher deformation resistance as well as higher absorption power. Further investigations will be directed to improve

ose a most acceptable density of foam.

Railway Safety, Passive Safety, Foam Filled Seamless Tube, Experimental Investigations, Polyurethane

The research work is funded by the Ministry of Education, Science and Technological DeRepublic of Serbia, Projects TR35045 and TR35031.

31





POLYURETHANE FOAM ON

ENERGY ABSORBER , Dragan D. Milkovic1

University of Belgrade, Faculty of Mechanical Engineering, Department of Rail Vehicles, 11000 Belgrade,

Đinđića, Belgrade, Serbia

Safety of railway vehicles is one of the most importance steps in developing and design of them. Passive nces of collision to a minimal by absorbing collision kinetic

energy. Applying a proper standard and adequate design of railway vehicle structure has a direct impact on safety of railway traffic. One of many ways for collision energy absorption is the tube energy absorber which works on the principle of shrinking the foam filled tube passing through special cone bushing. Fill made from high density polyurethane has a role to increase deformation resistance during elastic-plastic deformation of

mless tube was made from low carbon steel while the cone bushing was made from quench and tempered carbon steel. This type of absorber is designed to install in a line (behind) with standard buffer.

plastic deformation of the tube, friction between the tube and cone bushing and pressing of the foam. With the aim to show influence of the density of the foam on absorption power, experimental investigations of tubes filled by polyurethane foam of different density were done. Results of experimental investigations show that increase of density gives higher deformation resistance as well as higher absorption power. Further investigations will be directed to improve

Railway Safety, Passive Safety, Foam Filled Seamless Tube, Experimental Investigations, Polyurethane

The research work is funded by the Ministry of Education, Science and Technological Development of


STRUCTURAL OPTIMIZAT

1*University of Belgrade, Faculty of Mechanical Engineering, Kraljice

Corresponding author e

Abstract

The main aim of many researchers is to solve the problem of shape optimization of the pressure vessels in order to save materials and energy during manufacturing, but preserve relStructural optimization of several parameters that have main impact on stress, strain and deformation stateof the pressure vessels is presented in this research. Modern approach of stress and strain analysis on pressure vessels involves numerical and experimental testing. Experimental 3D Digital Image Correlation (DIC) method for analysing full field of surface strain and stress including camera system in combination with Aramis software was used. After determination of areas wconcentrations, numerical analysis of equivalent 3D model was performed in Ansys Workbench software. Results in critical areas were compared and they showed good agreement. Then, several parameters were chosen for optimization in order to reduce stresses and mass weight of pressure vessel. Response Surface Optimization (RSO) method was used to optimize geometry of the pressure vessel parts (shell, head and nozzles). It is shown that carried out optimization gives thoptimized wall and nozzle thicknesses for the given load.

Keywords

Structural optimization, pressure vessel, digital image correlation method, finite element analysis, response surface optimization method

Acknowledgement

This research was supported by Ministry of Education, Science and Technological Development of Republic of Serbia under Projects TR35031.



Zlatibor, July 0


STRUCTURAL OPTIMIZATION OF PRESSURE VESS

USING FEA Martina Balac*1



The main aim of many researchers is to solve the problem of shape optimization of the pressure vessels in to save materials and energy during manufacturing, but preserve reliability during exploitation.

Structural optimization of several parameters that have main impact on stress, strain and deformation stateof the pressure vessels is presented in this research. Modern approach of stress and strain analysis on

s involves numerical and experimental testing. Experimental 3D Digital Image Correlation full field of surface strain and stress including camera system in combination with

Aramis software was used. After determination of areas with highest von Mises stresses and strain concentrations, numerical analysis of equivalent 3D model was performed in Ansys Workbench software. Results in critical areas were compared and they showed good agreement. Then, several parameters were

optimization in order to reduce stresses and mass weight of pressure vessel. Response Surface Optimization (RSO) method was used to optimize geometry of the pressure vessel parts (shell, head and nozzles). It is shown that carried out optimization gives the minimum weight of pressure vessel with optimized wall and nozzle thicknesses for the given load.

Structural optimization, pressure vessel, digital image correlation method, finite element analysis, response


32





ION OF PRESSURE VESSELS


The main aim of many researchers is to solve the problem of shape optimization of the pressure vessels in iability during exploitation.

Structural optimization of several parameters that have main impact on stress, strain and deformation stateof the pressure vessels is presented in this research. Modern approach of stress and strain analysis on

s involves numerical and experimental testing. Experimental 3D Digital Image Correlation full field of surface strain and stress including camera system in combination with

ith highest von Mises stresses and strain concentrations, numerical analysis of equivalent 3D model was performed in Ansys Workbench software. Results in critical areas were compared and they showed good agreement. Then, several parameters were

optimization in order to reduce stresses and mass weight of pressure vessel. Response Surface Optimization (RSO) method was used to optimize geometry of the pressure vessel parts (shell, head and

e minimum weight of pressure vessel with

Structural optimization, pressure vessel, digital image correlation method, finite element analysis, response



EXPERIMENTAL MEASURE

IN THE LOWER LINK OF

Vera Cerovic1, Dragan Milkovic1University of Belgrade, Faculty of Mechanical Engineering, 11000 Belgrade, Serbia


Abstract

Agricultural machines and their implements are subjected to dynamic loads during farm operations. Depending on the type of operation (e.g. lifting or plowing), lower links of the threeare exposed to stresses caused by combination of bending moments and axial forces. In this paper we analysed influence of the soil resistance during plowing on the lower link and the possibility of stresses were measured using strain gauges at locations with unimore reliable comparison with finite element analysis (FEA). Recorded stresses vs. time were used for identifying mean stresses and amplitudes for different plowing depth and different tractor speeds. Due to the geometry of the lower links and their joints in the threetransferring soil resistance, links are loaded not only by axial forces but also by bending moment in the horizontal plane. Under some assumptions, FEA provstresses and the loads that caused them. Measured stresses show that links have significant safety margin relative to tractor installed power and soil resistance, which enables the possibility of their design optimization. Obtained results may also serve for further analyses of fatigue life prediction, measurement of the draft forces etc.

Keywords

Three-point hitch mechanism, lower link, stress state, strain gauges, finite element analysis

Acknowledgement

The authors express the gratitude to the Ministry of Education, Science and Technological Development, Republic of Serbia,research grantsTR 35006 and TR 35045.



Zlatibor, July 0


EXPERIMENTAL MEASUREMENTS OF THE STRESSE

IN THE LOWER LINK OF THE THREE-POINT HITCH

MECHANISM , Dragan Milkovic1*, Aleksandar Grbovic1, Sasa Radulovic1, Jovan Tanaskovic



Agricultural machines and their implements are subjected to dynamic loads during farm operations. Depending on the type of operation (e.g. lifting or plowing), lower links of the three

caused by combination of bending moments and axial forces. In this paper we influence of the soil resistance during plowing on the lower link and the possibility of

stresses were measured using strain gauges at locations with uniform stress distribution inmore reliable comparison with finite element analysis (FEA). Recorded stresses vs. time were used for

stresses and amplitudes for different plowing depth and different tractor speeds. Due to the geometry of the lower links and their joints in the three-point hitch mechanism, duringtransferring soil resistance, links are loaded not only by axial forces but also by bending moment in the horizontal plane. Under some assumptions, FEA provided us to make relations between the measured stresses and the loads that caused them. Measured stresses show that links have significant safety margin relative to tractor installed power and soil resistance, which enables the possibility of their design optimization. Obtained results may also serve for further analyses of fatigue life prediction, measurement of

hitch mechanism, lower link, stress state, strain gauges, finite element analysis

uthors express the gratitude to the Ministry of Education, Science and Technological Development, Republic of Serbia,research grantsTR 35006 and TR 35045.

33





MENTS OF THE STRESSES

POINT HITCH

, Jovan Tanaskovic1


Agricultural machines and their implements are subjected to dynamic loads during farm operations. Depending on the type of operation (e.g. lifting or plowing), lower links of the three-point hitch mechanism

caused by combination of bending moments and axial forces. In this paper we influence of the soil resistance during plowing on the lower link and the possibility of its failure. The

distribution in order to enable more reliable comparison with finite element analysis (FEA). Recorded stresses vs. time were used for

stresses and amplitudes for different plowing depth and different tractor speeds. Due to the mechanism, during plowing and

transferring soil resistance, links are loaded not only by axial forces but also by bending moment in the ided us to make relations between the measured

stresses and the loads that caused them. Measured stresses show that links have significant safety margin relative to tractor installed power and soil resistance, which enables the possibility of their design optimization. Obtained results may also serve for further analyses of fatigue life prediction, measurement of

hitch mechanism, lower link, stress state, strain gauges, finite element analysis

uthors express the gratitude to the Ministry of Education, Science and Technological Development,


MULTIPARAMETER STRUC

PRESSURE VESSEL WITHMartina Balac

1University of Belgrade, Faculty of Mechanical Engineering, 11000 Belgrade, Serbia


Abstract

Structural analysis of pressure equipment (vessels) has alwayPressure vessels are usually subjected to different loads in exploitation and small defects can lead to failure of the equipment, which may result in loss of life, health hazards and damage of property.of stress and strain analysis of the influence of welded nozzles on pressure vessels involves numerical and experimental testing. In this research, 3D Digital Image Correlation (DIC) method for analysing full field surface strain and stress, including determination of critical areas with highest von Mises stresses and strain concentrations, numerical analysis of equivalent 3D model was performed in Ansys Workbench software. The aim of thdetailed parameter optimization of pressure vessel with two nozzles based on finite element analysis (FEA) of the structure. Several geometrical parameters were varied to obtain the optimum geometry of the pressure vessel, capable of withstanding the service load without plastic deformation.optimization gives the minimum weight of pressure vessel with optimized wall and nozzle thicknesses for the given load.

Keywords

Pressure vessel, Digital Image Correlamethod

Acknowledgement

Study presented in this paper is part of the project TR 35031 financed by Ministry of Education, Science and Technological Development of Republic of Serbia.



Zlatibor, July 0


MULTIPARAMETER STRUCTURAL OPTIMIZATION O

PRESSURE VESSEL WITH TWO NOZZLESMartina Balac1, Aleksandar Grbovic1



Structural analysis of pressure equipment (vessels) has always been a huge challenge for researchers. Pressure vessels are usually subjected to different loads in exploitation and small defects can lead to failure

, which may result in loss of life, health hazards and damage of property.of stress and strain analysis of the influence of welded nozzles on pressure vessels involves numerical and experimental testing. In this research, 3D Digital Image Correlation (DIC) method for analysing full field surface strain and stress, including camera system in combination with Aramis software, was used. After determination of critical areas with highest von Mises stresses and strain concentrations, numerical analysis of equivalent 3D model was performed in Ansys Workbench software. The aim of th

parameter optimization of pressure vessel with two nozzles based on finite element analysis (FEA) of the structure. Several geometrical parameters were varied to obtain the optimum geometry of the pressure

withstanding the service load without plastic deformation. It is shown that carried out optimization gives the minimum weight of pressure vessel with optimized wall and nozzle thicknesses for the

Pressure vessel, Digital Image Correlation method, finite element analysis, optimization, response surface

Study presented in this paper is part of the project TR 35031 financed by Ministry of Education, Science and Technological Development of Republic of Serbia.

34





TURAL OPTIMIZATION OF

TWO NOZZLES


s been a huge challenge for researchers. Pressure vessels are usually subjected to different loads in exploitation and small defects can lead to failure

, which may result in loss of life, health hazards and damage of property. Modern approach of stress and strain analysis of the influence of welded nozzles on pressure vessels involves numerical and experimental testing. In this research, 3D Digital Image Correlation (DIC) method for analysing full field

camera system in combination with Aramis software, was used. After determination of critical areas with highest von Mises stresses and strain concentrations, numerical analysis of equivalent 3D model was performed in Ansys Workbench software. The aim of this paper is to present

parameter optimization of pressure vessel with two nozzles based on finite element analysis (FEA) of the structure. Several geometrical parameters were varied to obtain the optimum geometry of the pressure

It is shown that carried out optimization gives the minimum weight of pressure vessel with optimized wall and nozzle thicknesses for the

tion method, finite element analysis, optimization, response surface

Study presented in this paper is part of the project TR 35031 financed by Ministry of Education, Science and


STRAIN MEASUREMENT SETUP

LOADED MANDIBLE MODE

Milos Milosevic1*, Srdan Posti

1University of Belgrade, Innovation Centre of th2University of Belgrade, School of Dental Medicine

3University of Belgrade, 4Technical University of Kosice with a


Abstract

In this study, the setup for strain measurement of loaded mandible modepresented. During mastication, bite forces exert compressive loads on mandible and teeth. If compensations are present in a patient, failure might occur on toothtooth design resulting in uneven strain distribution. Difference in hardness of teeth and compensations has an additional impact on failure at the location of contact. Obtaining strain field underneath the teeth in ‘’in vitro’’ measurement is substantial in predictinStrain field was measured using contactless optical 3D system ARAMIS 2.0.Aset consisting of two accurately correlated cameras allows recording of relative movement, based on whichProper calibration of the device is substantial for acquisition of results. Mandible models are manufactured using additive technology, allowing for versatile and repeatable results compared to previous researches which included cadaver mandible models.alloy. Loads are transmitted through a vise, in a force range of 0force measurement. Developed experimental setup allows for application of different cap designs on different set of teeth. Results show how this setup enables comparison of influence of different shapes of compensation and teeth on strain distribution.

Keywords:

Dental, Mandible model, Strain field, Optical 3D measurement, ARAMIS 2.0

Acknowledgement

This research is funded by the support of the Ministry of Education through Contract grants: TR35040, TR35006



Zlatibor, July 0


IN MEASUREMENT SETUP OF COMPRESSIVELY

LOADED MANDIBLE MODEL WITH TEETH AND

COMPENSATIONS tic2,Nenad Mitrovic3,Aleksa Milovanovic1, Milan Travica

Hloch4, Zorana Golubovic3

Innovation Centre of the Faculty of Mechanical Engineering, 11000 Belgrade, Serbia

University of Belgrade, School of Dental Medicine, 11000 Belgrade, Serbia


Technical University of Kosice with a seat in Presov, Faculty of Manufacturing Technologies, 08001 Slovakia


In this study, the setup for strain measurement of loaded mandible model with teeth and compensations is presented. During mastication, bite forces exert compressive loads on mandible and teeth. If compensations are present in a patient, failure might occur on tooth-compensation contact due to inadequate processed

n resulting in uneven strain distribution. Difference in hardness of teeth and compensations has an additional impact on failure at the location of contact. Obtaining strain field underneath the teeth in ‘’in vitro’’ measurement is substantial in predicting possible failure. Strain field was measured using contactless optical 3D system ARAMIS 2.0.Aset consisting of two accurately

cameras allows recording of relative movement, based on which the strain field was obtained. e device is substantial for acquisition of results. Mandible models are manufactured

using additive technology, allowing for versatile and repeatable results compared to previous researches which included cadaver mandible models. Compensation caps of different design are all made of CoCrMo

Loads are transmitted through a vise, in a force range of 0-150N. Dynamometer is used for applied Developed experimental setup allows for application of different cap designs on different

teeth. Results show how this setup enables comparison of influence of different shapes of and teeth on strain distribution.

Dental, Mandible model, Strain field, Optical 3D measurement, ARAMIS 2.0

ded by the support of the Ministry of Education and Science of the Republic of Serbia TR35040, TR35006 and TR35031.

35





OF COMPRESSIVELY

L WITH TEETH AND

, Milan Travica1, Sergej

Faculty of Mechanical Engineering, 11000 Belgrade, Serbia

, 11000 Belgrade, Serbia


Technologies, 08001 Presov,

l with teeth and compensations is presented. During mastication, bite forces exert compressive loads on mandible and teeth. If compensations

compensation contact due to inadequate processed n resulting in uneven strain distribution. Difference in hardness of teeth and compensations has

an additional impact on failure at the location of contact. Obtaining strain field underneath the teeth in ‘’in

Strain field was measured using contactless optical 3D system ARAMIS 2.0.Aset consisting of two accurately the strain field was obtained.

e device is substantial for acquisition of results. Mandible models are manufactured using additive technology, allowing for versatile and repeatable results compared to previous researches

rent design are all made of CoCrMo 150N. Dynamometer is used for applied

Developed experimental setup allows for application of different cap designs on different teeth. Results show how this setup enables comparison of influence of different shapes of

and Science of the Republic of Serbia

36

Numerical Methods


DETERMINATION OF FRA

PARAMETERS OF STRUCT

UNDER THERMOMECHANICMaksimovic S. Katarina1, Vasovic V. Ivana

1City Administration of City of Belgrade, Secretariat for Utilities and Housing Services Water Management, Kraljice

2*Research and Development Institute Lola L.T.D., 70A Kneza3 Belgrade Waterworks and Sewerage, Kneza

4IDS Industrieservice Anlagenbau GmbH, Max Planck Ring 40, 46049 Oberhausen, German


Abstract

Aircraft structural components of general turbine components. It operates at high temperatureoxidation, corrosion and wear. During the service of turbine, components suffer from initiation and increasing tip cracks. These conditions can cause cracking of structural components. The failuturbine are classified in terms of main components as flow path parts, rotating such as rotor, groove, disk, and blade. Aero-engine turbine components such as disks and blades are susceptible to environmentally assisted cracking. Unlike fatigue crack growth, this involves crack growth under constant load. If the crack grows long enough, sudden failure can occur with catastrophic consequences. It is therefore desirable to identify the limiting crack size within fixings so that they can be from service before failure occurs. Three dimensional axisimulate a turbine disc and the portion of a blade. The finite element method allowed the prediction of thepoint of crack initiation and the crack growth using the orientations of the maximum principal stresses. Stress intensity factor (SIF) is the base parameter in strength analysis regarding fracture mechanics. For correct determination SIF in this paper, coindependent integral around the crack tip.

Keywords

Fatigue, thermomechanical loads, cracked components,

Acknowledgement

This work was financially supported by the Ministry of Science and Technological Development of Serbia under Projects OI-174001 and TR-35045.



Zlatibor, July 0

Numerical Methods

DETERMINATION OF FRACTURE MECHANICS

PARAMETERS OF STRUCTURAL COMPONENTS

THERMOMECHANICAL LOADS, Vasovic V. Ivana2*,Maksimovic S. Mirko3, Dragi Stamenkovic

City Administration of City of Belgrade, Secretariat for Utilities and Housing Services Water Management, Kraljice Marije 1,11000 Belgrade, Serbia

ch and Development Institute Lola L.T.D., 70A Kneza Viseslava Street, 11030 Belgrade, Serbia

Belgrade Waterworks and Sewerage, Kneza Milosa st. 27, 11000 Belgrade, Serbia

Anlagenbau GmbH, Max Planck Ring 40, 46049 Oberhausen, German


Aircraft structural components of general turbine and wing skin in high Mach number flow are important at high temperature and under conditions of extreme environmental attack such as

oxidation, corrosion and wear. During the service of turbine, components suffer from initiation and increasing tip cracks. These conditions can cause cracking of structural components. The failuturbine are classified in terms of main components as flow path parts, rotating such as rotor, groove, disk,

engine turbine components such as disks and blades are susceptible to environmentally fatigue crack growth, this involves crack growth under constant load. If the crack

grows long enough, sudden failure can occur with catastrophic consequences. It is therefore desirable to identify the limiting crack size within fixings so that they can be inspected at regular intervals and removed from service before failure occurs. Three dimensional axi-symmetric finite element models were created to simulate a turbine disc and the portion of a blade. The finite element method allowed the prediction of thepoint of crack initiation and the crack growth using the orientations of the maximum principal stresses. Stress intensity factor (SIF) is the base parameter in strength analysis regarding fracture mechanics. For correct determination SIF in this paper, combining J-integral approach and FEM is used. Jindependent integral around the crack tip.

Fatigue, thermomechanical loads, cracked components, fatigue crack growth, low-cycle fatigue,

supported by the Ministry of Science and Technological Development of Serbia 35045.

37




al Methods

CTURE MECHANICS

COMPONENTS

AL LOADS , Dragi Stamenkovic4

City Administration of City of Belgrade, Secretariat for Utilities and Housing Services Water Management,

Viseslava Street, 11030 Belgrade, Serbia

st. 27, 11000 Belgrade, Serbia

Anlagenbau GmbH, Max Planck Ring 40, 46049 Oberhausen, Germany

skin in high Mach number flow are important and under conditions of extreme environmental attack such as

oxidation, corrosion and wear. During the service of turbine, components suffer from initiation and increasing tip cracks. These conditions can cause cracking of structural components. The failure damage modes of turbine are classified in terms of main components as flow path parts, rotating such as rotor, groove, disk,

engine turbine components such as disks and blades are susceptible to environmentally fatigue crack growth, this involves crack growth under constant load. If the crack

grows long enough, sudden failure can occur with catastrophic consequences. It is therefore desirable to inspected at regular intervals and removed

symmetric finite element models were created to simulate a turbine disc and the portion of a blade. The finite element method allowed the prediction of the point of crack initiation and the crack growth using the orientations of the maximum principal stresses. Stress intensity factor (SIF) is the base parameter in strength analysis regarding fracture mechanics. For correct

integral approach and FEM is used. J-integral is path

cycle fatigue, SIF

supported by the Ministry of Science and Technological Development of Serbia


AN OPEN SOURCE SOFTW

COMPUTATIONAL CONTINNikola Mirkov

1University of Belgrade, Institute of Nuclear Sciences Energy, Mike Petrovića

2University of Belgrade, Faculty of Traffic Engineering, Vojvode


Abstract

The paper describes development of an opencomputational continuum mechanics. The code is based polyhedral meshes. The interfaces to highly abstract data types such as arbitrary order tensor fields on discretized finite volume domains, and scalar and vector sparse linear systems resulting from finite discretization of partial differential equations are provided. Explicit manipulation of tensor fields through high level, highly abstract programming syntax is explained. Also, implicit operation over tensor fields pertinent to discretization of partial differential operators is provided and explained. The library is developed in modern version of Fortran. Code parallelization is achieved through domain decomposition and implemented using MPI and Open MP. While avoiding the usual class syntax of objeessentially object oriented design purpose of the ongoing development is providing researchers with a tool for easy transfer of mathematical operations of their physical models into functional and efficient simulation software based on finite volume method. The guiding principle of development is exchange of ideas and reproducibility in computational science in general.

Keywords

Engineering Software, Computational Fluid Dynamics, Finite Volume Method, Parallel Computing, HighPerformance Computing

Acknowledgement

Support of the Ministry of Education, Science and Technological Development of republic of Serbia, trough project TR-33036 is greatly acknowledged.



Zlatibor, July 0

Numerical Methods

AN OPEN SOURCE SOFTWARE LIBRARY FOR

COMPUTATIONAL CONTINUUM MECHANICSNikola Mirkov1*, Nenad Vidanovic2, Gordana Kastratovic

of Belgrade, Institute of Nuclear Sciences - Vinča, Laboratory for Thermal Engineering and Energy, Mike Petrovića Alasa 12-14, 11351 Belgrade, Serbia

University of Belgrade, Faculty of Traffic Engineering, Vojvode Stepe 305, 11010, Belgrade, Serbia

esponding author e-mail: [email protected]

The paper describes development of an open-source library for computational fluid dynamics and in general computational continuum mechanics. The code is based on finite volume method on arbitrary unstructured polyhedral meshes. The interfaces to highly abstract data types such as arbitrary order tensor fields on discretized finite volume domains, and scalar and vector sparse linear systems resulting from finite discretization of partial differential equations are provided. Explicit manipulation of tensor fields through high level, highly abstract programming syntax is explained. Also, implicit operation over tensor fields pertinent to

tial differential operators is provided and explained. The library is developed in modern version of Fortran. Code parallelization is achieved through domain decomposition and implemented using

While avoiding the usual class syntax of object-oriented programming, the code has .Comparison is made with the well-known Open

purpose of the ongoing development is providing researchers with a tool for easy transfer of mathematical their physical models into functional and efficient simulation software based on finite volume

method. The guiding principle of development is exchange of ideas and reproducibility in computational

tional Fluid Dynamics, Finite Volume Method, Parallel Computing, High

Support of the Ministry of Education, Science and Technological Development of republic of Serbia, trough 33036 is greatly acknowledged.

38




al Methods

ARE LIBRARY FOR

UUM MECHANICS Gordana Kastratovic2

Vinča, Laboratory for Thermal Engineering and 14, 11351 Belgrade, Serbia

Stepe 305, 11010, Belgrade, Serbia

source library for computational fluid dynamics and in general on finite volume method on arbitrary unstructured

polyhedral meshes. The interfaces to highly abstract data types such as arbitrary order tensor fields on discretized finite volume domains, and scalar and vector sparse linear systems resulting from finite volume discretization of partial differential equations are provided. Explicit manipulation of tensor fields through high level, highly abstract programming syntax is explained. Also, implicit operation over tensor fields pertinent to

tial differential operators is provided and explained. The library is developed in modern version of Fortran. Code parallelization is achieved through domain decomposition and implemented using

oriented programming, the code has known Open FOAM library. The

purpose of the ongoing development is providing researchers with a tool for easy transfer of mathematical their physical models into functional and efficient simulation software based on finite volume

method. The guiding principle of development is exchange of ideas and reproducibility in computational

tional Fluid Dynamics, Finite Volume Method, Parallel Computing, High-

Support of the Ministry of Education, Science and Technological Development of republic of Serbia, trough


APPLICATION OF FINIT

DETERMINATION OF AXI

Zarko Miskovic1, Radivoje Mitrovic1University of Belgrade, Faculty of Mechanical Engineering, 11000 Belgrade, Serb

2Tehnikum Taurunum, College of Applied Sciences,

3Slovak University of Technology in Bratislava, Institute of Transport Technology and Designing, Faculty of Mechanical Engineering, Bratislava, Slovakia


Abstract

The impact of the axial load is often completely neglected in the design of the conveyor idlers (rollers) testing machines. The subject of the present research is focused primarby numerical simulation of the contact between the conveyor belt and idlers. A nonlinear theory of the finite element method is applied, taking into account the effects of large displacements and the contact prThe basic information required for the presented calculation was the modulus of elasticitybelt in the lateral direction. An experimental apparatus in accordance with the DIN 22102 standard wasdeveloped and used to determine the lomodelling was initially checked by the simulation of the designed experimental testing. A significant match of the results confirmed the applicability of the presented approach to the modellingThe axial load on the wing (side) idlers is generated only during the partial loading of the conveyor. It has considerably high intensity only until the conveyor belt touches the horizontal idler. Applying the gradually increasing load on the conveyor belt in the numerical model and monitoring the vertical distance between the belt and the horizontal conveyor idler, the exact moment of contact was determined. The reaction forces registered in the contact of the belt and the wing designed conveyor idlers testing machine of the radial and axial load.

Keywords

Conveyor idlers, finite element simulations, testing pr

Acknowledgement

The authors would like to express their sincere gratitude to the Ministry of Education, Science and Technological Development of Republic of Serbia for the support, as well as for the equipment used, acquired within the national project TR35029.



Zlatibor, July 0

Numerical Methods

APPLICATION OF FINITE ELEMENT METHOD FOR

DETERMINATION OF AXIAL LOAD ON CONVEYOR

WING ROLLERS Radivoje Mitrovic1, Milan Tasic2, Marko Tasic2 and Ján Danko

University of Belgrade, Faculty of Mechanical Engineering, 11000 Belgrade, Serb

Tehnikum Taurunum, College of Applied Sciences, 11080 Belgrade, Serbia

University of Technology in Bratislava, Institute of Transport Technology and Designing, Faculty of Mechanical Engineering, Bratislava, Slovakia


The impact of the axial load is often completely neglected in the design of the conveyor idlers (rollers) testing machines. The subject of the present research is focused primarily on the conveyor idlers load determination by numerical simulation of the contact between the conveyor belt and idlers. A nonlinear theory of the finite element method is applied, taking into account the effects of large displacements and the contact prThe basic information required for the presented calculation was the modulus of elasticitybelt in the lateral direction. An experimental apparatus in accordance with the DIN 22102 standard wasdeveloped and used to determine the load representative value. The adopted approach to the numerical modelling was initially checked by the simulation of the designed experimental testing. A significant match of the results confirmed the applicability of the presented approach to the modelling of the considered problem. The axial load on the wing (side) idlers is generated only during the partial loading of the conveyor. It has considerably high intensity only until the conveyor belt touches the horizontal idler. Applying the gradually

ng load on the conveyor belt in the numerical model and monitoring the vertical distance between the belt and the horizontal conveyor idler, the exact moment of contact was determined. The reaction forces registered in the contact of the belt and the wing idlers are used as the experimental loads in the custom designed conveyor idlers testing machine – where conveyor idlers are tested under the simultaneous action

Conveyor idlers, finite element simulations, testing procedure, mechanical design.

The authors would like to express their sincere gratitude to the Ministry of Education, Science and Technological Development of Republic of Serbia for the support, as well as for the equipment used,

hin the national project TR35029.

39




al Methods

E ELEMENT METHOD FOR

AL LOAD ON CONVEYOR

and Ján Danko3



University of Technology in Bratislava, Institute of Transport Technology and Designing, Faculty of

The impact of the axial load is often completely neglected in the design of the conveyor idlers (rollers) testing ily on the conveyor idlers load determination

by numerical simulation of the contact between the conveyor belt and idlers. A nonlinear theory of the finite element method is applied, taking into account the effects of large displacements and the contact problems. The basic information required for the presented calculation was the modulus of elasticity of the conveyor belt in the lateral direction. An experimental apparatus in accordance with the DIN 22102 standard was

ad representative value. The adopted approach to the numerical modelling was initially checked by the simulation of the designed experimental testing. A significant match of

of the considered problem. The axial load on the wing (side) idlers is generated only during the partial loading of the conveyor. It has considerably high intensity only until the conveyor belt touches the horizontal idler. Applying the gradually

ng load on the conveyor belt in the numerical model and monitoring the vertical distance between the belt and the horizontal conveyor idler, the exact moment of contact was determined. The reaction forces

idlers are used as the experimental loads in the custom where conveyor idlers are tested under the simultaneous action

The authors would like to express their sincere gratitude to the Ministry of Education, Science and Technological Development of Republic of Serbia for the support, as well as for the equipment used,


EXPERIMENTAL INVESTI

BEHAVIOUR OF AL 2024 ALLOY WEL

Miodrag Milcic1, Toma1Faculty of Mechanical Engineering

2University of Maribor, Faculty of Mechanical Engineering, Smetanova3Military Technical Institute, Ratka

*Corresponding author e-mail:

Abstract

The Aluminium alloy 2024 plates of 6 mm thickness are welded in circular butt joint geometry by Welding (FSW) process, using the vertical milling machine. The paper presents the results of structural and mechanical testing of the alloyed aluminiumresearch was to know the relationship between welding parameters and mechanical and microstructural properties of 2024 joints. The rotation speed of the tool did not change and amounted to 750 rpm, and the welding speed was 73, 116, 150 mm/min. The welded joints obtained were free of erracceptable flat surface. Tensile tests were performed orthogonally in the direction of welding on samples. This variation of tensile strength with rotational speeds for a given traverse speed appears to be linked to the energy of the welds.Joint efficiency as high as 97% of base metal could be achieved at 750/116 rpm/(mm/min). Microtests were performed on each sample at three different heights of 0.5 mm from the face, in the middle and 0.5 mm from the root of the weld. The best mecvalue of the welding speed. The testing of welded joints was also performed on bending, around the face, and around the root. Comparing the obtained bending test results, the largest bend angle to phenomenon is for welding parameters 750/116 rpm/(mm/min) and amounts to 42°. The value of impact strength increases with welding speed from 73 mm/min to 116 mm/min. But the value of impact strength slightly decreases as the welding speeultimate tensile strength.

Keywords

Friction stir welding, aluminium alloy 2024, microstructural properties, mechanical properties



Zlatibor, July 0

Numerical Methods

EXPERIMENTAL INVESTIGATION OF MECHANICAL

OF AL 2024 ALLOY WELDED BY FRICTION

STIR WELDING , Tomaz Vuherer2, Igor Radisavljevic3, Dragan

Faculty of Mechanical Engineering University of Niš, Aleksandra Medvedeva 14, 18000 Niš, Serbia

University of Maribor, Faculty of Mechanical Engineering, Smetanova ulica 17, 2000 Maribor, Slovenia

Military Technical Institute, Ratka Resanovića 1, 11000 Beograd, Serbia

mail: [email protected]; [email protected]

The Aluminium alloy 2024 plates of 6 mm thickness are welded in circular butt joint geometry by Welding (FSW) process, using the vertical milling machine. The paper presents the results of structural and

aluminium alloys AA 2024 welded by the FSW process. The goal of the nship between welding parameters and mechanical and microstructural

properties of 2024 joints. The rotation speed of the tool did not change and amounted to 750 rpm, and the welding speed was 73, 116, 150 mm/min. The welded joints obtained were free of err

Tensile tests were performed orthogonally in the direction of welding on samples. This variation of tensile strength with rotational speeds for a given traverse speed appears to be linked to the energy of the welds.Joint efficiency as high as 97% of base metal could be achieved at 750/116 rpm/(mm/min). Microtests were performed on each sample at three different heights of 0.5 mm from the face, in the middle and 0.5 mm from the root of the weld. The best mechanical strength conditions were obtained using the "mean" value of the welding speed. The testing of welded joints was also performed on bending, around the face, and around the root. Comparing the obtained bending test results, the largest bend angle to phenomenon is for welding parameters 750/116 rpm/(mm/min) and amounts to 42°. The value of impact strength increases with welding speed from 73 mm/min to 116 mm/min. But the value of impact strength slightly decreases as the welding speed increases from 116 mm/min to 150 mm/min, which is consistent with

alloy 2024, microstructural properties, mechanical properties

40




al Methods

GATION OF MECHANICAL

DED BY FRICTION

Milcic1

iš, Aleksandra Medvedeva 14, 18000 Niš, Serbia

ulica 17, 2000 Maribor, Slovenia

Resanovića 1, 11000 Beograd, Serbia

[email protected]

The Aluminium alloy 2024 plates of 6 mm thickness are welded in circular butt joint geometry by Friction Stir Welding (FSW) process, using the vertical milling machine. The paper presents the results of structural and

alloys AA 2024 welded by the FSW process. The goal of the nship between welding parameters and mechanical and microstructural

properties of 2024 joints. The rotation speed of the tool did not change and amounted to 750 rpm, and the welding speed was 73, 116, 150 mm/min. The welded joints obtained were free of errors and with an

Tensile tests were performed orthogonally in the direction of welding on samples. This variation of tensile strength with rotational speeds for a given traverse speed appears to be linked to the energy of the welds. Joint efficiency as high as 97% of base metal could be achieved at 750/116 rpm/(mm/min). Micro-Vickers tests were performed on each sample at three different heights of 0.5 mm from the face, in the middle and

hanical strength conditions were obtained using the "mean" value of the welding speed. The testing of welded joints was also performed on bending, around the face, and around the root. Comparing the obtained bending test results, the largest bend angle to the first cracking phenomenon is for welding parameters 750/116 rpm/(mm/min) and amounts to 42°. The value of impact strength increases with welding speed from 73 mm/min to 116 mm/min. But the value of impact strength

d increases from 116 mm/min to 150 mm/min, which is consistent with

alloy 2024, microstructural properties, mechanical properties


COMPUTATIONAL STUDY

PATHWAY IN ALZHEI

1


Abstract

Wnt (named after wingless gene in Drosophilia) signalling pathway is structure and function of the adult brain. It is found following areas of brain: frontal cortex, cerebellum, hippocampal formation, basal forebrain, and olfactory bulb. Damage or dysfunction of brain cells in these areas can cause many diseases. Here we are concerned with Alzheimer disease, which is connected with impairment of learning and memory this disease also attacks other areas of bradisease are formation of toxic amyloid beta plaques and neurofibrille tangles that leads to neural cell death or prevent normal function of cell. In this paper we consider Wnt signalling mechanismconnected with Alzheimer disease. It is indirectly or directly connected with formation of plaques or tangles. Here we present set of biochemical reactions that mathematical model. Based on the experimental data from the literature we run simulations and provide computational investigation of the model. We determine key acters and molecules and we look for the regulating molecules as possible targets for drug departicipates in diverse biological processes that includes neurogenesis, axonal remodelling, formation and maintenance of pre and post synaptic terminals, and in excitatory synaptic other human diseases such as cancer, metabolic diseases, coronary disease, diabetes and obesity, etc.

Keywords

Wntsignalling pathway, Alzheimer disease, biochemical reactions, mathematical model, computational study



Zlatibor, July 0

Numerical Methods

COMPUTATIONAL STUDY OF WNT SIGNALING

PATHWAY IN ALZHEIMER DISEASENatasa A. Kablar1



Wnt (named after wingless gene in Drosophilia) signalling pathway is important in the regulation of the f the adult brain. It is found that activity of Wnt signalling pathway is present in the

following areas of brain: frontal cortex, cerebellum, hippocampal formation, basal forebrain, and olfactory of brain cells in these areas can cause many diseases. Here we are concerned

with Alzheimer disease, which is connected with impairment of learning and memory this disease also attacks other areas of brain and consequently other functions. Hallmarks of Alzheimer disease are formation of toxic amyloid beta plaques and neurofibrille tangles that leads to neural cell death or prevent normal function of cell. In this paper we consider Wnt signalling mechanismconnected with Alzheimer disease. It is indirectly or directly connected with formation of plaques or tangles. Here we present set of biochemical reactions that underlie this signalling, and we derive consequent

sed on the experimental data from the literature we run simulations and provide computational investigation of the model. We determine key acters and molecules and we look for the regulating molecules as possible targets for drug development. Wnt signalling

in diverse biological processes that includes neurogenesis, axonal remodelling, formation and maintenance of pre and post synaptic terminals, and in excitatory synaptic transmission

seases such as cancer, metabolic diseases, coronary disease, diabetes and obesity, etc.

pathway, Alzheimer disease, biochemical reactions, mathematical model, computational study

41




al Methods

OF WNT SIGNALING

MER DISEASE

[email protected]

important in the regulation of the that activity of Wnt signalling pathway is present in the

following areas of brain: frontal cortex, cerebellum, hippocampal formation, basal forebrain, and olfactory of brain cells in these areas can cause many diseases. Here we are concerned

with Alzheimer disease, which is connected with impairment of learning and memory in basal forebrain, but in and consequently other functions. Hallmarks of Alzheimer

disease are formation of toxic amyloid beta plaques and neurofibrille tangles that leads to neural cell death or prevent normal function of cell. In this paper we consider Wnt signalling mechanism which is found to be connected with Alzheimer disease. It is indirectly or directly connected with formation of plaques or tangles.

this signalling, and we derive consequent sed on the experimental data from the literature we run simulations and provide

computational investigation of the model. We determine key acters and molecules included in the pathway velopment. Wnt signalling

in diverse biological processes that includes neurogenesis, axonal remodelling, formation and transmission. It is also found in

seases such as cancer, metabolic diseases, coronary disease, diabetes and obesity, etc.

pathway, Alzheimer disease, biochemical reactions, mathematical model, computational study


NUMERICAL METHODS IN

IMPLANT Katarina Colic1*, Aleksandar Grbovi1University of Belgrade, Innovation Center of Faculty of Mechanical Engineering, Belgrade, Serbia

2University of Belgrade, Faculty of Mechanical Engineer3Sebha University


Abstract

In this paper a numerical investigation of replacement implant for partial hip aelement analysis (FEA) was performed using threebehaviour of the femoral component at forces ranging from 3.5kN to 6.0 kN. This implant design was chosen for numerical analysis because stress concentration in femoral component lead to implant fracture. Metallic alloys are used for orthopaedic prosthesis, and its femoral head and stem are often made of cobaltchromium alloy. Results show that the force magnitudes acting on the ican cause implant stress field changes and implant stability problems, which can lead to implant failure.

For the simulation of crack propagation extended finite element method (XFEM) was used, as being one of the most advanced modelling techniques for this type of problem. Extended finite element method (XFEM) used enhancement functions as a means of displaying all forms of discontinuous behaviour, such as crack displacement. Enhancement functions are introduced into tnumber of finite elements, relative to the size of the whole domain. Short theoretical background information on the XFEM is provided, as well as the representation of crack and the stress intensity factors co In order to evaluate the influence of initial defects in material on strength and life of structures, finite element analysis is applied to cracks of various shapes, sizes and locations. In these analyses, FEM is limited, since changes in crack topology require additional generating of mesh domain. This represents a significant constraint and complicates crack growth simulation on complex geometries. Extended finite element method, X-FEM was developed in order to make calculations easier, which arbitrary cracks within a finite element model.

Keywords:

Hip Implant, Stress Intensity Factor, FEM,

Acknowledgement

The research work is funded by the support of the Serbia - Contract grants: TR 35040.

.



Zlatibor, July 0

Numerical Methods

UMERICAL METHODS IN ASESSMENT

IMPLANT DESIGN AND INTEGRITYAleksandar Grbovic2, Aleksandar Sedmak2, Kaled Legweel

Innovation Center of Faculty of Mechanical Engineering, Belgrade, Serbia

University of Belgrade, Faculty of Mechanical Engineering, Belgrade, Serbia

Sebha University, Sebha High Institute, Sabha, Libya


In this paper a numerical investigation of replacement implant for partial hip arthroplasty is presented. A finite element analysis (FEA) was performed using three-dimensional models to examine the mechanical behaviour of the femoral component at forces ranging from 3.5kN to 6.0 kN. This implant design was chosen

s because stress concentration in femoral component lead to implant fracture. Metallic alloys are used for orthopaedic prosthesis, and its femoral head and stem are often made of cobaltchromium alloy. Results show that the force magnitudes acting on the implant are of interest, and that they can cause implant stress field changes and implant stability problems, which can lead to implant failure.

For the simulation of crack propagation extended finite element method (XFEM) was used, as being one of advanced modelling techniques for this type of problem. Extended finite element method (XFEM)

used enhancement functions as a means of displaying all forms of discontinuous behaviour, such as crack displacement. Enhancement functions are introduced into the displacement approximation for only a small number of finite elements, relative to the size of the whole domain. Short theoretical background information on the XFEM is provided, as well as the representation of crack and the stress intensity factors co

In order to evaluate the influence of initial defects in material on strength and life of structures, finite element analysis is applied to cracks of various shapes, sizes and locations. In these analyses, FEM is limited, since

topology require additional generating of mesh domain. This represents a significant constraint and complicates crack growth simulation on complex geometries. Extended finite element method,

FEM was developed in order to make calculations easier, which was required during positioning of arbitrary cracks within a finite element model.

ntensity Factor, FEM, Numerical Simulations, Extended Finite Element Method

the support of the Ministry of Education and Science of the Republic of

42




al Methods

ASESSMENT OF HIP

INTEGRITY Kaled Legweel3, Uros Tatic1

Innovation Center of Faculty of Mechanical Engineering, Belgrade, Serbia

ing, Belgrade, Serbia

rthroplasty is presented. A finite dimensional models to examine the mechanical

behaviour of the femoral component at forces ranging from 3.5kN to 6.0 kN. This implant design was chosen s because stress concentration in femoral component lead to implant fracture. Metallic

alloys are used for orthopaedic prosthesis, and its femoral head and stem are often made of cobalt-mplant are of interest, and that they

can cause implant stress field changes and implant stability problems, which can lead to implant failure.

For the simulation of crack propagation extended finite element method (XFEM) was used, as being one of advanced modelling techniques for this type of problem. Extended finite element method (XFEM)

used enhancement functions as a means of displaying all forms of discontinuous behaviour, such as crack he displacement approximation for only a small

number of finite elements, relative to the size of the whole domain. Short theoretical background information on the XFEM is provided, as well as the representation of crack and the stress intensity factors computation.

In order to evaluate the influence of initial defects in material on strength and life of structures, finite element analysis is applied to cracks of various shapes, sizes and locations. In these analyses, FEM is limited, since

topology require additional generating of mesh domain. This represents a significant constraint and complicates crack growth simulation on complex geometries. Extended finite element method,

was required during positioning of

Numerical Simulations, Extended Finite Element Method

Ministry of Education and Science of the Republic of

43

New Technologies


USAGE OF DC

IN SOLAR APPLICATIONSIvana Vlajic Naumovska

1The School of Electrical and Compute2University of Belgrade, Mihajlo Pupin Institute, 11000 Belgrade, Serbia

3University of Belgrade, School of electrical engineering, Department of Power grids and systems, 11000

*Correspon

Abstract

The paper presents one possible application of the "buck" converter, i.e. the voltage down regulator in the system for supplying LED lighting from solar panels. The "LED lamp. In this paper, the calculation of the system components, i.e. the dimensioning of the inverter, solar panel and accumulator battery according to the needs and requirements of the system for the LED lamp, is given. A special accent is given on the calculation of active components (switching transistor and diode) and passive components (choke and capacitor) of the "buck" converter. In addition, a synchronous converter is alused instead of the diode. Based on the calculation of the components of the converter, a simulation circuit was generated and a simulation of the batterywas made. Three operating modes with different values of DC input voltage 15 V, 24 V and 28 V. were analysed. With all these modes, it has been proven that this type of converter meets load requirements of a LED flashlight. On the basis of the obtained results, it was concluded that it is possible to practically implement one such system, with acceptable power losses, as well as with the acceptable efficiency for the average daily insolation that is present in these areas for 4 hours.

Keywords

DC-DC converter, Buck converter, MOSFET, Light Emitting Diode, PSPICE



Zlatibor, July 0

New Technologies

USAGE OF DC-DC CONVERTERS

IN SOLAR APPLICATIONS Ivana Vlajic Naumovska1*, Zeljko Despotovic2, Borko Cupic

The School of Electrical and Computer Engineering of Applied Studies, Belgrade, Serbia

University of Belgrade, Mihajlo Pupin Institute, 11000 Belgrade, Serbia

University of Belgrade, School of electrical engineering, Department of Power grids and systems, 11000 Belgrade, Serbia


The paper presents one possible application of the "buck" converter, i.e. the voltage down regulator in the system for supplying LED lighting from solar panels. The "Buck" converter is used to stabilize the voltage on LED lamp. In this paper, the calculation of the system components, i.e. the dimensioning of the inverter, solar panel and accumulator battery according to the needs and requirements of the standsystem for the LED lamp, is given. A special accent is given on the calculation of active components (switching transistor and diode) and passive components (choke and capacitor) of the "buck" converter. In addition, a synchronous converter is also considered in the work, so the MOSFET switching transistor is used instead of the diode. Based on the calculation of the components of the converter, a simulation circuit was generated and a simulation of the battery-converter-consumer system in the PSPwas made. Three operating modes with different values of DC input voltage 15 V, 24 V and 28 V. were

. With all these modes, it has been proven that this type of converter meets load requirements of a s of the obtained results, it was concluded that it is possible to practically

implement one such system, with acceptable power losses, as well as with the acceptable efficiency for the average daily insolation that is present in these areas for 4 hours.

DC converter, Buck converter, MOSFET, Light Emitting Diode, PSPICE

44




New Technologies

DC CONVERTERS

, Borko Cupic31

r Engineering of Applied Studies, Belgrade, Serbia

University of Belgrade, Mihajlo Pupin Institute, 11000 Belgrade, Serbia

University of Belgrade, School of electrical engineering, Department of Power grids and systems, 11000

The paper presents one possible application of the "buck" converter, i.e. the voltage down regulator in the Buck" converter is used to stabilize the voltage on

LED lamp. In this paper, the calculation of the system components, i.e. the dimensioning of the inverter, solar stand-alone power supply

system for the LED lamp, is given. A special accent is given on the calculation of active components (switching transistor and diode) and passive components (choke and capacitor) of the "buck" converter. In

so considered in the work, so the MOSFET switching transistor is used instead of the diode. Based on the calculation of the components of the converter, a simulation circuit

consumer system in the PSPICE software package was made. Three operating modes with different values of DC input voltage 15 V, 24 V and 28 V. were

. With all these modes, it has been proven that this type of converter meets load requirements of a s of the obtained results, it was concluded that it is possible to practically

implement one such system, with acceptable power losses, as well as with the acceptable efficiency for the


WIRELESS ROBOT ARM C

ARDUINO MICROCONTROL

1


Abstract

Robot arm can be designed for educational or prototype purposes. It can be designed in CAD program, with .nc or .sty files produced in CAM program. It can be further used NC machine or 3D printparts for robot arm. Further, we propose wireless robot arm controller based on Arduino board with microcontroller. Components needed are also four DC generic motors to drive base, shoulder, elbow and hand of robot arm, Bluetooth HC-05 orAndroid smartphone to Arduino board, breadboard or protoboard to place and connect components in electrical circuit, jumper wires, and battery. Further, we for control of robot arm from smartphone. Also, it is needed to make code for Arduino responds to input commands, process them, and produce outputs toward DC motors in order to provide movement of robotic arm. For that we will need Arduino IDE software environment. We provide block diagram of components connection, and direction how to assembly it. Robot arm can be further prototyped and tested. It can be used for educational or prototype purposes.

Keywords

Robot arm, wireless control, Arduino



Zlatibor, July 0

New Technologies

WIRELESS ROBOT ARM CONTROL BASED ON

ARDUINO MICROCONTROLLERNatasa A. Kablar1*



Robot arm can be designed for educational or prototype purposes. It can be designed in CAD program, with .nc or .sty files produced in CAM program. It can be further used NC machine or 3D printparts for robot arm. Further, we propose wireless robot arm controller based on Arduino board with microcontroller. Components needed are also four DC generic motors to drive base, shoulder, elbow and

05 or Wi-Fi HC-12 module to receive and transfer command controls from Android smartphone to Arduino board, breadboard or protoboard to place and connect components in electrical circuit, jumper wires, and battery. Further, we need iShield for Android smartphonfor control of robot arm from smartphone. Also, it is needed to make code for Arduino

to input commands, process them, and produce outputs toward DC motors in order to provide at we will need Arduino IDE software environment. We provide block

diagram of components connection, and direction how to assembly it. Robot arm can be further prototyped and tested. It can be used for educational or prototype purposes.

Arduino microcontroller, educational prototype

45




New Technologies

ONTROL BASED ON

LER

[email protected]

Robot arm can be designed for educational or prototype purposes. It can be designed in CAD program, with .nc or .sty files produced in CAM program. It can be further used NC machine or 3D printer to manufacture parts for robot arm. Further, we propose wireless robot arm controller based on Arduino board with microcontroller. Components needed are also four DC generic motors to drive base, shoulder, elbow and

12 module to receive and transfer command controls from Android smartphone to Arduino board, breadboard or protoboard to place and connect components in

for Android smartphone and application for control of robot arm from smartphone. Also, it is needed to make code for Arduino microcontroller which

to input commands, process them, and produce outputs toward DC motors in order to provide at we will need Arduino IDE software environment. We provide block

diagram of components connection, and direction how to assembly it. Robot arm can be further prototyped


ACCURACY OF POLYMER ELECTROLY

(PEM) FUEL CELL REFO

FDM AND SLA 3D PRINT

COMPARISON WITH DIGIAleksa Milovanovic1; Milos Milos

1University of Belgrade, Innovation Centre of the 2University of Belgrade, Faculty of Mechanical Engineering, Department of

3Department of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Ljubljana,

*Corresponding

Abstract

The subject of this paper is the evaluation of accuracy of FDM and SLA 3D printing technologies, in comparison with developed reformer polymer electrolyte membrane (PEM) fuel cell CAD model. technologies allow bottom-up approach to manufacDimensional inaccuracy is still a problem in 3D printing technologies due to material shrinking and residual stress. Materials used in this research are PLA (resin material for SLA technology. Both materials are commonly used for 3D printing and have good dimensional stability. PLA material is printed in three different resolutions: 0.3mm, 0.2mm and 0.1mm. White resin is printed in 0.1mm resolution. dimensional accuracy of FDM models and to compare dimensional accuracy of FDM and SLA printing technologies.

Keywords

Reformer, 3D printing, FDM, SLA, CAD model

Acknowledgement

This research is carried out under the NATO SPS Project EAP.SFPP 984738, and the Ministry of Education and Science of the Republic of Serbia projects TR35040, TR35006 and III 43007.



Zlatibor, July 0

New Technologies

OF POLYMER ELECTROLYTE MEMBRANE

(PEM) FUEL CELL REFORMER PROTOTYPES USIN

FDM AND SLA 3D PRINTING TECHNOLOGY IN

COMPARISON WITH DIGITAL CAD MODELMilos Milosevic1; Goran Mladenovic2; Blaz Likozar3; Katarina Colic

Mitrovic2

Innovation Centre of the Faculty of Mechanical Engineering, 11000 Belgrade, Serbia

University of Belgrade, Faculty of Mechanical Engineering, Department of Production Engineering, 11000 Belgrade, Serbia

Department of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Ljubljana, Slovenia


The subject of this paper is the evaluation of accuracy of FDM and SLA 3D printing technologies, in comparison with developed reformer polymer electrolyte membrane (PEM) fuel cell CAD model.

up approach to manufacturing, depositing material in layers to final shape. Dimensional inaccuracy is still a problem in 3D printing technologies due to material shrinking and residual stress. Materials used in this research are PLA (Polylactic Acid) for FDM technology and stanresin material for SLA technology. Both materials are commonly used for 3D printing and have good dimensional stability. PLA material is printed in three different resolutions: 0.3mm, 0.2mm and 0.1mm. White resin is printed in 0.1mm resolution. The aim of this paper is to show how different printing resolutions affect dimensional accuracy of FDM models and to compare dimensional accuracy of FDM and SLA printing

Reformer, 3D printing, FDM, SLA, CAD model

research is carried out under the NATO SPS Project EAP.SFPP 984738, and the Ministry of Education and Science of the Republic of Serbia projects TR35040, TR35006 and III 43007.

46




New Technologies

TE MEMBRANE

RMER PROTOTYPES USING

ING TECHNOLOGY IN

TAL CAD MODEL ; Katarina Colic1; Nenad


Production Engineering, 11000

Department of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Ljubljana,

The subject of this paper is the evaluation of accuracy of FDM and SLA 3D printing technologies, in comparison with developed reformer polymer electrolyte membrane (PEM) fuel cell CAD model. 3D printing

, depositing material in layers to final shape. Dimensional inaccuracy is still a problem in 3D printing technologies due to material shrinking and residual

Acid) for FDM technology and standard white resin material for SLA technology. Both materials are commonly used for 3D printing and have good dimensional stability. PLA material is printed in three different resolutions: 0.3mm, 0.2mm and 0.1mm. White

The aim of this paper is to show how different printing resolutions affect dimensional accuracy of FDM models and to compare dimensional accuracy of FDM and SLA printing

research is carried out under the NATO SPS Project EAP.SFPP 984738, and the Ministry of Education


MANUFACTURING AND GE

OF PARTS WITH FREE FGoran M. Mladenovic1, Marko J. Milovanovic

1University of Belgrade, Faculty of Mechanical Engineering, Department of Production Engineering, 11000

2Deutsches Elektronen3University of Liverpool, Department of Physics, Oliver Lodge Laboratory, Liverpool, United Kingdom


Abstract

Based on several years of research at the Department of Production Engineering, Faculty of Mechanical engineering, University of Belgrade, Serbia, form surfaces has been developed. Using this software, a tool path forform surfaces was generated. The main goal of the conducted research was to generate a tool path with minimal machining time whilst not compromising the machining quality. A multicriteria tmethod was used, in particular the feed rate variation method, in order to obtain a control code (NC) that would allow machining with constant cutting force. Manufacturing of the parts was done at the Mechanical Engineering Faculty in Belgrade, using the ILR HMC 500/40 tool system, according to generated control codes. During the manufacturing it was concluded that the machining of these parts was performed with constant cutting force. Geometrical measurements of manufactured parts werof Physics - University of Liverpool, UKmeasurements of the manufactured parts were performed using two methods; contact (touch probe) and contactless (optical) whereby a point cloud of data was obtained. Using the MATLABprogram code was written that generates a map of the deviation based on the difference between the loaded point cloud and the CAD model. Finally, by machining was performed within defined specifications. This demonstrated that the developed system is a useful for tool path generation for parts with free form surfaces.

Keywords

Computer graphics, CAD/CAM systems, F

Acknowledgement

The author wishes to thank the Ministry of Science and Technological Development of Serbia for providing financial support that made this work possible (Project TR 35022). We are aUniversity of Liverpool, Department of physics and all the help in finalizing this project.



Zlatibor, July 0

New Technologies

MANUFACTURING AND GEOMETRY MEASURE

OF PARTS WITH FREE FORM SURFACES, Marko J. Milovanovic2, Ljubodrag M. Tanovic1, Tim J. Jones

Pjevic1

University of Belgrade, Faculty of Mechanical Engineering, Department of Production Engineering, 11000 Belgrade, Serbia

Deutsches Elektronen-Synchrotron (DESY), Zeuthen, Germany

University of Liverpool, Department of Physics, Oliver Lodge Laboratory, Liverpool, United Kingdom


research at the Department of Production Engineering, Faculty of Mechanical iversity of Belgrade, Serbia, software for automatic tool path generation for parts with free

form surfaces has been developed. Using this software, a tool path for machining of different parts with free form surfaces was generated. The main goal of the conducted research was to generate a tool path with minimal machining time whilst not compromising the machining quality. A multicriteria tmethod was used, in particular the feed rate variation method, in order to obtain a control code (NC) that would allow machining with constant cutting force. Manufacturing of the parts was done at the Mechanical

Belgrade, using the ILR HMC 500/40 tool system, according to generated control codes. During the manufacturing it was concluded that the machining of these parts was performed with constant cutting force. Geometrical measurements of manufactured parts were performed at the

University of Liverpool, UK using OGP Smartscope CNC 624 multisensor metrology system. The measurements of the manufactured parts were performed using two methods; contact (touch probe) and

hereby a point cloud of data was obtained. Using the MATLABprogram code was written that generates a map of the deviation based on the difference between the loaded point cloud and the CAD model. Finally, by analysing generated maps of deviation, it was concluded that the machining was performed within defined specifications. This demonstrated that the developed system is a useful for tool path generation for parts with free form surfaces.

Computer graphics, CAD/CAM systems, Free form surfaces, Tool path optimization, Map of deviation

The author wishes to thank the Ministry of Science and Technological Development of Serbia for providing financial support that made this work possible (Project TR 35022). We are also very thankful to people from University of Liverpool, Department of physics – Particle Physics Group and DESY for excellent collaboration and all the help in finalizing this project.

47




New Technologies

OMETRY MEASUREMENT

ORM SURFACES , Tim J. Jones3, Milos D.

University of Belgrade, Faculty of Mechanical Engineering, Department of Production Engineering, 11000

Y), Zeuthen, Germany

University of Liverpool, Department of Physics, Oliver Lodge Laboratory, Liverpool, United Kingdom

research at the Department of Production Engineering, Faculty of Mechanical software for automatic tool path generation for parts with free

machining of different parts with free form surfaces was generated. The main goal of the conducted research was to generate a tool path with minimal machining time whilst not compromising the machining quality. A multicriteria tool path optimization method was used, in particular the feed rate variation method, in order to obtain a control code (NC) that would allow machining with constant cutting force. Manufacturing of the parts was done at the Mechanical

Belgrade, using the ILR HMC 500/40 tool system, according to generated control codes. During the manufacturing it was concluded that the machining of these parts was performed with

performed at the Department Smartscope CNC 624 multisensor metrology system. The

measurements of the manufactured parts were performed using two methods; contact (touch probe) and hereby a point cloud of data was obtained. Using the MATLAB

® software package, a

program code was written that generates a map of the deviation based on the difference between the loaded f deviation, it was concluded that the

machining was performed within defined specifications. This demonstrated that the developed system is a

ree form surfaces, Tool path optimization, Map of deviation

The author wishes to thank the Ministry of Science and Technological Development of Serbia for providing lso very thankful to people from

Particle Physics Group and DESY for excellent collaboration

CIP- Каталогизација у публикацији

Народна библиотека Србије

621(048)(0.034.2)

62:519.6(048)(0.034.2)

INTERNATIONAL Conference of Experimental and Numerical Investigations and New

Technologies (2018 ; Zlatibor)

Programme [Elektronski izvor] ; and The Book of abstracts /

International Conference of Experimental and Numerical Investigations and New

Technologies - CNN TECH 2018, 04-06 July 2018, Zlatibor ; organized by

Innovation Center of Faculty of Mechanical Engineering [and] Faculty of

Mechanical Engineering, University of Belgrade [and] Center for Business

Trainings ; [editors Nenad Mitrovic, Milos Milosevic, Goran Mladenovic]. -

Belgrade : Faculty of Mechanical Engineering, Innovation Center, 2018 (Belgrade

: Faculty of Mechanical Engineering, Innovation Center). - 1 elektronski optički

disk (CD-ROM) ; 12 cm

Sistemski zahtevi: Nisu navedeni. - Nasl. sa naslovne strane dokumenta

ISBN 978-86-7083-979-3

1. Faculty of Mechanical Engineering. Innovation Center (Beograd)

a) Машинство - Апстракти

b) Техника - Нумерички методи - Апстракти

COBISS.SR-ID 265505292

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