simulation techniques in manufacturing technology · 28. okt l 53c/101 ozhoga-maslovskaja forming...

© WZL/Fraunhofer IPT

Simulation Techniques in

Manufacturing Technology

Introduction

Laboratory for Machine Tools and Production Engineering

Chair of Manufacturing Technology

Prof. Dr.-Ing. Dr.-Ing. E.h. Dr. h.c. Dr. h.c. F. Klocke

Seite 2 © WZL/Fraunhofer IPT

Optimization integration in the FEM 9

FE model validation 8

FE modelling for the cutting process 7

FE modelling for the forming process 6

Lecture topics and fundamental knowledge 5

Modelling and simulation: Definition, motivation and integration 4

Lecture objectives 3

Presentation of WZL 2

Lecture organisation 1

Outline


STMT-Lecture: Time schedule

Time:

Lecture (L): Fr, 10.00-11.30h

Exercise (E): Fr, 11.45-12.30h

Location: WZL, RWTH Aachen

Herwart-Opitz-Haus

Steinbachstr. 53

52074 Aachen

Room: 53C, 101

Contact: Dr.-Ing. M. Abouridouane

Tel. (0241) 80-28176

Date Typ Room No. Lecturer Topic

21. Okt L 53C/101 Abouridouane Introduction to STMT

53B, R312b

28. Okt L 53C/101 Ozhoga-Maslovskaja Forming technology basics

28. Okt E 53C/101 54A, R411

04. Nov L 53C/101 Ozhoga-Maslovskaja Actual simulation techniques in forming process

54A, R411

11. Nov. L 53C/101 Ozhoga-Maslovskaja Bulk metal forming

54A, R411

18. Nov L 53C/101 Ozhoga-Maslovskaja Sheet metal forming and separation

18. Nov E 53C/101 54A, R411

25. Nov L 53C/101 Abouridouane Principles of Cutting

25. Nov E 53C/101 53B, R312b

02. Dez L 53C101 Abouridouane Overview of the various cutting processes

02. Dez E 53C/101 53B, R312b

09. Dez L 53C/101 Abouridouane FE-Simulation of cutting processes

53B, R312b

16. Dez W 53B/101a Abouridouane FEM-Workshop (Abaqus and Deform)

16. Dez W 53B/101a Ozhoga-Maslovskaja

13. Jan L 53C101 Barth Cutting with geometrically undefined cutting edge I

13. Jan E 53C101 54A, R403

20. Jan L 53B/101a Barth Cutting with geometrically undefined cutting edge II

20. Jan E 53B/101a 54A, R403

27. Jan L 53B/101a Abouridouane Methods of validation and optimization techniques

27. Jan E 53B/101a 53B, R312b

03. Feb L 53C/101 Abouridouane Revision of contents

03. Feb E 53C/101 53B, R312b


STMT-Lecture: Exam, computer exercise, literature

Examination

– Type of examination: Oral

– Date of the examination: February, the xxth 2017

– Room, time, and distribution of groups will be given!

– Duration: 60 minutes for each group

Computer exercise

– Date for the FEM-Workshop: December, the 16th 2016

– Room: 53B/101a (WZL, Herwart-Opitz-Haus)

– Time: 10:00 to 18:00

Literature about metal machining (Emails list!)

– Manufacturing processes 1 - Cutting of Klocke

– Metal Machining (Theory and Applications) of Childs

– Machining Dynamics of Kai Cheng

Any other discussion points, comments or questions?

– Please contact Mr. Abouridouane (Tel.: +49 241 80-28176)


STMT-Lectutre: Supervisors

Cutting process

Forming process

Grinding process

Dr.-Ing. Mustapha Abouridouane

Herwart-Opitz-Haus 53B 312b

Tel.: +49 241 80-28176

Fax: +49 241 80-22293

[email protected]

Dr.-Ing. Oksana Ozhoga-Maslovskaja

Herwart-Opitz-Haus 54A 411

Tel.: +49 241 80-27428

Fax: +49 241 80-22293

[email protected]

M.Sc. RWTH Sebastian Barth

Herwart-Opitz-Haus 54A 403

Tel.: +49 241 80-28183

Fax: +49 241 80-22293

[email protected]

mailto:[email protected]





















Outline


RWTH Aachen and Fraunhofer-Gesellschaft

RWTH Aachen University

Founded in 1870

40,375 students

Faculty of Mechanical Engineering

11,700 students

(incl. 2,700 first year students)

53 professors

2,600 employees

170 graduates per year

Fraunhofer-Gesellschaft

More than 65 institutes und facilities

at 40 locations in Germany

>23,000 employees

approx. € 2.0 billion research funds

per year, € 1.7 billion through research contracts

3 institutes in Aachen


Production Technology in Aachen

Laboratory for Machine Tools

and Production Engineering (WZL)

RWTH Aachen University institute

Founded in 1906

839 employees

16,000 m² offices and laboratories

Fraunhofer Institute for Production Technology IPT

Fraunhofer-Gesellschaft institute

Founded in 1980

450 employees

6300 m² offices and laboratories

Certified to DIN EN ISO 9001:2008


Budget 2013: WZL, Fraunhofer IPT, WZLforum, WZL Aachen GmbH

Industrial projects 41.70 %

Public funding* 33.57 %

Basic funding by 24.73 %

Fraunhofer-Gesellschaft and

RWTH Aachen University

Budget: 53.61 Mio €

* EU, AiF, BMBF, DFG


Two Institutes – One Philosophy

Process Technology

Production Machines

Mechatronic Systems Design

Production Quality and Metrology

Technology Management

Manufacturing Technology

Gearing Technology

Machine Tools

Metrology and Quality Management

Production Engineering and

Production Management


Our Focus

Process Technology

Machining and material removal

processes

Laser materials processing

Forming processes

CAx, Virtual Reality

Production and Machine Tools

Design of production machines

and components

Control technology and automation

Component and production machines

testing

Metrology

Tactile metrology

Optical metrology

Management

Business Engineering

Technology management

Innovation management

Production management

Quality management

Education

Professional training

Executive MBA for Technology Managers

Conferences, congresses, seminars

Gearing Technology

Gear manufacturing

Gear calculation and

investigation


Grinding and forming

Solid forming,

sheet metal

forming, hard

smooth rolling,

tribology

Turning,

milling,

drilling,

broaching

Cutting

technology

CAD/CAM

technologies

CAx

technologies

Process and Manufacturing Technology

Process and

product

monitoring

Material

removal

processes

Process moni-

toring systems

and strategies

Prof. Dr.-Ing. Dr.-Ing. E.h. Dr. h.c. Dr. h.c. Fritz Klocke

Laser machining

Rapid

Manufacturing

Laser surface

treatment Joining,

cutting,

forming

Tool and die making

Precision and micro technology

Optics and optical systems

Plant engineering and construction

Automotive, aerospace, turbine construction

Grinding,

lapping,

polishing,

honing


Process and Manufacturing Technology

Manufacturing fundamentals

Machining with a geometrically defined cutting edge

Machining with a geometrically undefined cutting edge

Material removal processes

Forming processes

Laser machining

Gearwheel manufacture

Precision and ultra-precision processes

Process and product monitoring

Process simulations, methods and tools for technology planning and production design, virtual reality


Fundamentals of Cutting

Concept for

cooling

lubricants

Manufacturing Technology:

Group: Fundamentals of Cutting & Modeling and Evaluation

Modeling and Evaluation

Modelling and

model

development

Simulation of

tool wear

Machin-

ability

Analysis

of wear

Process

Design

Tool

development

Energy-saving

production

Technology

planning

Space- and aircraft-industry, turbine construction (machining of turbine disks and blades, structural components..)

Bild Bild Bild

Automotive industry (processing of crankcase, cylinder head, cylinder, camshaft, axle parts…)

Tool technology (wear analysis, tool layout, macro , micro geometry…)

Materials manufacturer (machinability, lead substitute …)

Resource efficiency (material, energy, auxiliaries…)


Virtuelle Realität

Analysis of the machinability

Material analysis of tools and

components, analysis of tool wear

Process development and process

optimisation in turning, milling,

drilling, broaching, tapping

Development of machining

strategies, HSC and HPC

machining, circular processes

Development and optimisation of

lubricooling strategies: dry, MQL,

conventional wet, high-pressure and

cryogenic

Tool development: substrate, macro

and micro geometry, cutting edge

preparation, coating, chip form

geometry

Development of environmentally

friendly and resource efficient

machining processes

Chair of Manufacturing Technology

Group Fundamentals of Cutting


Virtuelle Realität

Simulation of

cutting processes

Calculation of the

workpiece distortion

Energy and material

measurement and assessment

Energetic and environmental

evaluation of cutting processes

Chair of Manufacturing Technology –

Modelling and Evaluation of Cutting Processes

Selection

Modelling of cutting processes

Development of process models for

cutting technologies

Simulation of the thermo-mechanical

load spectrum during machining

Cutting tool design and optimization of

process parameters using FEM-

simulations

Evaluation of cutting processes

Acquiring and assessing of energy and

material consumptions of single

processes (indicators)

Evaluation and design of processes

and technology chains in respect to

energy and resource efficiency

Ecological life cycle management and

Life cycle assessment (LCA)

Makroskopisches

FEM-Modell

Berechnung des thermo-

mechanischen Bleastungskollektiv

Berechnung des Spanungsquerschnittes auf der Grundlage

der Durchdringung von Werkstück und Werkzeug

Methodik

InputWerkzeuggeometrie

Werkstückgeometrie

TCP, vc und f

Durchdringungsrechnung

Makrogeometrie nach der

spanenden Bearbeitung

Output Aktueller Spanungs-

querschnitt, vc und f

VW erkstü ck

W erk zeu gSp an

v c

Zerspankraft

Temperatur

T(t+t)

F(t+t)











Outline


Lecture objectives

Fundamentals and basic knowledge in manufacturing

technology for a better understanding of the mechanisms

during metal machining

Modelling approachs for simulation

Simulation techniques

Application of simulation in manufacturing technology

Challenges of simulation and future developments











Outline


Perception

Modelling – a human property

Experience Model vision


Sensorium

Modelling – a human property

IT-based converting

Modeling

Reality / Perception Mind


Basic of reasons

Deductive

reasoning

Modeling based on

theoretical derived

models

Inductive

reasoning

Modeling

based on

experience

The particular

Reality

The general

Model section

I n

d u

c t

i v

D e

d u

c t

i v


Simulation

A simulation is a replication of a dynamic process based on a model.

Model

A model is an abstract system that corresponds to a real system

and is used for expensive and/or impossible

- investigations,

- calculations and

- explanations or demonstration purposes.

It delivers general information about

- elements,

- structure and

- behavior

of a part of the reality.

Definitions


Continuously increasing demands of the market lead to

increasing requirements for manufacturing processes.

Motivation

Product

– innovative

– reliable

– cost-effective

Components

– high quality

– high precision

– long product life

Manufacturing process

– economic

– reproducible

– flexible


Why process modelling?

Car Body

Time Cost

Quality

Increase quality

Apply new materials

(Al, Mg, …)

Use material more

efficiently

Reduction of tool

cost

Reduction of lead

time

Reduction of time

required for training

Increase reliability

of production

Manufacture complex parts

Reduction of

pre production trials

Source: BMW


Integration of process modelling into the process chain

Source: BMW

Design

of car

exterior

Part

design

Part

production

Means of production Tool manu-

facturing

and testing Tool design Planning

Sheet metal forming simulation

Part evaluation Process optimisation

So

ftw

are

so

luti

on

A

pp

lic

ati

on

P

roc

es

s c

ha

in

Methods applied: - 2D modelling

- one-step modelling

- modelling with membrane elements Short computation time with sufficient

precision

Methods applied: - Simulation with membrane elements

- Simulation with shell elements

High Precision within acceptable

computation times


specification sheet

product

concept design and

choice of material

lay-out

manufacturing aspects

design

manufacturing planning

manufacturing

workpiece test

4

12

16

8

24

12

Manufacturing tests

FEM-Calculation

Today without process simulation

Modelling and Simulation: aims and requirements

Increase of the process

knowledge & comprehension

Prediction of the process

stability

Prediction of the component

characteristics

Reduction of planning and

development steps

Cost reduction

Goals

76 W

eeks


4

12

14

12

12

Future with process simulation





stability


characteristics


development steps

Cost reduction

Goals

54 W

eeks

FEM

specification sheet

product

concept design and

choice of material

lay-out

design

manufacturing planning

manufacturing

workpiece test

Reduction of the cycle time by 30%

Simulation


High process reliability

High result quality

Realistic prediction of the

process results

Adaption of technological

innovations





stability


characteristics


development steps

Cost reduction

Goals

Requirements


Partitioning of different model types from literature review

ANN

models

4 %

Rule & knowledge

models 6%

Overview article 2 %

Analytical models 38 %

kinematic geometrical

models 10 %

FEA - models

19 %

Basic & regression

models 20 %

MD - models 1%

Source: Heinzel 2009


The history of the development of cutting process models

Source: Ivester, 50th CIRP General Assembly, Sidney 2000; *Heinzel 2009

1937 1947 1957 1967 1977 1987 1997

2D, Thin Zone, Analytic

3D, Empirical, Mechanistic

3D, Analytic

2D, FEM

2D, Thick zone, Slip-line

The use*

Analytical models: 38%

Basic and regression models: 20%

FEA models: 19%

Kinematic geometrical models: 10%

Rule and knowledge models: 6%

ANN models: 4%

Overview article: 2%

MD models: 1%











Outline


Sheet Metal Forming Techniques

Ironing Bending

Stretch forming Spinning

Hydroforming

Deep drawing


Forming process: Extruding a transmission shaft


Face milling


Grinding process


Lattice Types of an Unit Cell

face-centred

cubic

(fcc)

body-centred

cubic

(bcc)

hexagonal

(hex)

examples:

sliding planes:

sliding directions:

sliding systems:

formability:

γ-Fe, Al, Cu

4

3

12

very good

α-Fe, Cr, Mo

6

2

12

good

Mg, Zn, Be

1

3

3

poor


tensile test compression test shear test

F

F

l0

A0

l1

A1

A0 F

F

A1

l1

l0

0A

F

0A

F

Stress Determination Depending on Load

0A

F

F

F a

l

q

A0

tensile stress compression stress shear stress


Strain Determination of an Idealized Upsetting Process

00

01

00

1

0

l

l

l

ll

l

dl

l

dld

l

l

xx

0

1

0

1

0

1 ln ;ln ;lnh

h

b

b

l

lzyx

0

1ln1

0l

l

l

dl

l

dld

l

l

engineering strain (elastic)

true strain (plastic)

including of volume constancy

)1( ln l

l

l

l ln

l

ll ln

l

ul ln

l

l ln

0

0

00

0

0

x0

0

1

xx

const. 111000 bhlbhl

0 zyx

connection between true strain - engineering strain


Stress-Strain Curve up to the Uniform Elongation

A

F

0

str

ess

strain

engineering stress: (related to starting section)

F

F

Rm

Re ,se

eel epl

l0

l

l

A0

A

load

relieving reload

A

F

true tensile stress: (related to real section)

σ‘ σ


Flow curve

Flo

w s

tress k

f

True strain

Required stress to overcome

strain hardening

Minimal required stress for

initial plastic deformation


Stress conditions with corresponding Mohr's stress circles

Uniaxial

Biaxial

Triaxial


Yield criteria

Shear stress hypothesis by Tresca

𝜎2 = 𝜎3 = 0

𝜎1 =𝐹

𝐴= 𝑘𝑓 = 2𝑘 k =

kf

2

with 𝜏𝑚𝑎𝑥 𝜎1 − 𝜎3 = 𝑘𝑓

Form change – Energy hypothesis by von

Mises

𝜏𝑚𝑎𝑥 = 𝑘

𝜎3 𝜎1

𝜏

𝜎

𝑘𝑓 =1

2𝜎1 − 𝜎2

2 + 𝜎2 − 𝜎32 + 𝜎3 − 𝜎1

2

𝑘𝑓 =1

2max ( 𝜎1 − 𝜎2 , 𝜎2 − 𝜎3 , 𝜎3 − 𝜎1 )


The strain rate tensor and the deviatoric stress tensor are proportional to

each other (λ = proportionality factor).

Levy-Mises flow rule

Elastic Plastic

11

1

E

Hooke‘s law:

stress σ

strain εel

),(

fkf

Levy-Mises flow rule:

Mathematical dependence between yield stress and strain rate.

2

3

2

2

2

12

31

fk

m 11 m 22

m 33

Proportionality factor λ (not constant):

Mathematical dependence

between stress and strain.

Alternative form (division by dt):

Out of flow rule and v. Mises yield criterion follows:

mdd 22 mdd 11 mdd 33Flow rule:

yie

ld s

tress k

f

plastic strain φV


Yield stress and yield criterion

σr

σr

σz

σz

σt

σt

Assumption for plastic flow (v. Mises)

2

2132

32

2

21

fV k

σV

σV

Equivalent stress Yield criterion

σV = kf

F F

kf

Yield stress

kf

Real process

(multiaxial)

Determination of flow curves

(uniaxial)

F


Forming Property: Measuring Grid Technique

Deformation of the measuring grid because of tensile and compression stresses inside

the sheet metal while forming

The effective strain can be derived from the grid deformation = maximum deformation

(forming limit)

0

1b

d

bln

0

1l

d

lln


Forming Property: Forming Limit Curve

Determination of forming limit curve

to predict failure by using FEM

Quelle: ThyssenKrupp

Variable strip thickness to vary φ2 (one test

corresponds with one value of φ2)

Definition: φ1 > φ2

Strain φ2

Str

ain

φ1

Material: RR St 1403

Sheet thickness : 1 mm

“Well“

“Failure “

Test conditions:

deep drawing test with hemispherical

stamp and straight strip

Tenso-tenso

Tenso-

compressive











Outline


Considerations prior to a FE simulation study (Forming process)

Definition of the simulation problem

Objective of the simulation study

Relevant physical mechanisms:

– Mechanical, thermal, electro-magnetic…

Type of the problem:

– Linear

– Non-linear

Time dependency:

– Static

– Dynamic

Simulation software & hardware:

– Solvers for the intended objectives

– Element types

– Specific numerical technologies

Constituents of a model

Geometry

– Accurate form reproduction

– Stock or special FE mesh generator

– Critical areas, complex shapes

Material

– Material model formulation

– Elasticity and Poisson’s ratio

– Density, hardening

– Thermal properties

Boundary conditions

– Process parameters

– Process kinematics

– Process steps


Procedure of FE-Analysis

CAD-model

Idealization

Discretization

Boundary

conditions

FE-Analysis

Interpretation of

the results

Pre-processor

Solver

Post-processor

23

13

12

22

11

13

23

33

2212

1211

13

23

12

22

11

0000

0000

0000

000

000

G

G

G

GG

GG


FE Study process

CAD model

Idealization

Discretization

Material modeling

FE-Analyses

Evaluation

Boundary conditions

Geometry of a workpiece and a tool.

Often available as CAD Data.

Universal formats for 3D data (STEP, STP, STL…)

Simplification of the real geometry for a more structured mesh

Meshing of an object into discrete domains

Numerical reproduction of mechanic, kinematic, contact,

electro-magnetic, thermal conditions of a real process

Numerical formulation of relevant material properties

(elasticity, plasticity, shear etc.)

Calculation of elementary matrices, definition of the

system matrix and a vector of outer forces, solution of

linear equation systems for every integration point

Analysis of the results and answering the objective

of the study


Simulation of bulk metal forming processes

Chronology of FEM-Simulation: Material modelling

CAD model

Idealization

Discretization

Material modelling

FE-Analyses

Evaluation

Pre

pro

ce

ssor

So

lve

r P

ostp

ro.

Description of material behavior using

mathematical material models

Use of ideal-plastic material model is sufficient for

bulk metal forming processes

Use of elastoplastic material models for

simulation of sheet metal forming processes

Stress σ

Nominal strain ε

Elastic Ideal plastic

Plastic with

hardening

Elasto-plastic

with hardening

Boundary conditions Stress σ

Stress σ

Stress σ

Nominal strain ε

Nominal strain ε Nominal strain ε


Implicit solution method:

– Small number of time steps

(respectively long time increments)

– Higher effort for iterations compared to explicit

solution method

– Often less computation time then with explicit

solution method

– Applicable especially for static and

quasi-static problems

Explicit solution method:

– Length of increment depends on the speed of

sound c, Young‘s modulus E and material

density ρ; this requires a high number of

increments

– Longer computation time compared to implicit

solution method

– Applicable especially for highly dynamic

problems (e.g. crash-simulations)


Chronology of FEM-Simulation: FE-Analysis

CAD model

Idealization

Discretization

Material modelling

FE-Analyses

Evaluation

Pre

pro

ce

ssor

So

lve

r P

ostp

ro.

Boundary conditions



Movie: FEM-Simulation cross joint

Degree of damage Effective stress Mean stress

True strain Velocity field

Typical evaluation variables are stress-strain-profiles or

characteristic values such as the degree of damage.

CAD model

Idealization

Discretization

Material modelling

FE-Analyses

Evaluation

Boundary conditions











Outline


The great challenges of the cutting process

Source: Jaspers

Process Strain Strain rate / s-1 Thomolog

Extrusion 2 – 5 10-1 – 10-2 0.16 – 0.7

Forging /

Rolling 0.1 – 0.5 10 – 10+3 0.16 – 0.7

Sheet metal

forming 0.1 – 0.5 10 – 10+2 0.16 – 0.7

Cutting 1 – 5 10+3 – 10+6 0.16 – 0.9

Cutting process

Extreme conditions in the cutting process


Influence factors on the cutting process

Workpiece

µ-structure

Texture

Material

properties

Hardness

Residual stress

Cutting condition

Chip formation

mechanisms

Cooling lubricant

Cutting parameters

Contact

conditions

e. g.: Friction, heat

transfer, wear, etc.

Tool

Cutting material

Coating

Geometry

Tool holder

Machine

Machine design

Drive unit

Clamping device

Bild

eines

Prozesses

M


Input and output parameters of the cutting simulation

Tool

strain

stresses

temperatures

process forces

wear

Chip Formation

temperatures

stresses

deformations

strain rate

kind of chip

chip flow

chip breakage

Workpiece / Tool

geometries

material data

contact conditions

boundary conditions

cutting conditions

Workpiece

strain

temperatures

deformation

burr formation

distortion

prospective:

residual stresses,

surface qualities,

like: roughness,

dimensional- and formdeviation


Tool geometry modelling for a realistic tool CAD model

Macro-

geometry

4 mm

Drilling tool FE-CAD-Model Acquisition of tool geometry

Micro-

geometry

6 µm 6 µm

Real tool CAD-Model


Definition of element type


Material law to calculate stresses

i iB u


Thermo-mechanical behavior of material

Quelle: Diss-Abouridoaune

( , , )T

200

250

300

350

400

450

0 0.1 0.2 0.3 0.4

AA6063-T6

d/dt=10-3

s-1

& T=20°C

, -

,

M

Pa

300

350

400

450

10-3

10-1

101

103

AA6063-T6

=0.1 & T=20°C

d/dt , s-1

0

150

300

450

0 100 200 300 400 500

AA6063-T6

=0.1 & d/dt=1s-1

T , °C

Strain Rate HardeningStrain Hardening Thermal Softening

Source: Diss- Abouridouane


Empirical models: e.g. Johnson-Cook-Modell

Micro mechanical models: e.g. enhanced Macherauch-Vöhringer-Kocks-model

Semi-empirical models: e.g. Zerilli-Armstrong-model for bcc-materials

Constitutive material modelling for the FE cutting simulation

Source: Diss-Abouridouane

n -1/2

G 1 2 3 4 5σ = Δσ +C exp -C T +C Tln( ) +C +C L

Initial density

of dislocations Dislocation jam

Influence of temperature

and strain rate Influence of grain size

m

n r0

m r

T T(A B ) (1 Cln( / )) (1 )

T T

Strain hardening Strain rate sensitivity

Thermal softening

1/ p1/ q

* 0a 0

0

kT1 ·ln

G

Athermal processes Damping process

Thermal activated processes


Determination of High speed flow curves

Source: LFW

Split-Hopkinson-Pressure-Bar

AusgangsstabEingangsstab

Lager

Lager

Joch Projektil

Rohr

Zugprobe

Deckel mit

Luftanschluss

Pressluftbehälter mitSchnellöffnungsventil

AusgangsstabEingangsstab

Lager

Lager

Joch Projektil

Rohr

Zugprobe

Deckel mit

Luftanschluss

Pressluftbehälter mitSchnellöffnungsventil

Split-Hopkinson-Tension-Bar

Strain rate: 500 s-1 – 10000 s-1

Temperature range: 93 K – 1273 K

Projectile speed: 2,5 m/s – 50 m/s

Projectile mass: m = 3,15 kg

Joke Projectile Input rod Tensile specimen

Output rod

Tube Cover with air

connection

Air cylinder with

quick release valve

Lager LagerProbe

Temperier-

kammerAusgangsstabEingangsstab

Rohr

Preßluftbehälter

Projektil

AuffangbehälterCollection bag Sample

Input rod Output rod

Tube

Projectile

Air cylinder

Temperature

chamber

Bearing

Bearing Bearing

Bearing


Material law for high strain rate deformation

Quelle: Diss-Brodmann

dtBKa

BKk

n

n

adf

)(1

4 0 0

5 0 0

6 0 0

7 0 0

8 0 0

0 0 . 2 0 . 4 0 . 6 0 . 8

d / d t = 5 0 1 0 s

- 1

4 8 8 9 s - 1

4 3 5 0 s - 1

4 2 9 4 s - 1

3 4 5 0 s - 1

3 4 3 9 s - 1

2 5 5 8 s - 1

2 5 2 9 s - 1

0 . 0 0 1 s - 1

o : r

K = 9 6 0 M P a B = 0 . 0 3 1 n = 0 . 1 8 2

/ K = 6 . 2 5 · 1 0 - 6

s

A A 7 0 7 5 T 7 3 5 1 D r u c k v e r s u c h e

w

a h r e

S p a n n u n g , M

P a

True plastic strain, -

Lines: Calculation

Symbols: experiments

Pressure tests

Tru

e S

tress,

M

PA

Source: Diss- Brodmann


Material damage mechanisms

Quelle: Diss-Abouridouane

Type of load

Shear loading Tensile loading

TiAl6V4

20 µm 20 µm

Shear localisation model

(Imperfection theory)

Void growth model

(Hancock-Mackenzie)


Damage modelling for the FE cutting simulation (ductile failure)

Macromechanical damage models

– Effective stress / effective strain model: Dσ = σv,f / Dε = εv,f

– Gosh-Model: DGosh = (1+σ2/σ1) σ12

– Ayada-Model: dD = (σm/σv) dεv

Micromechanical damage models (Void expansion models)

– Hancock-Mackenzie-Model

– Gurson-Tveergard-Needleman-Model

– Johnson-Cook-Model

m

f 1 2 3 4 5

v 0 m

σ ε Tε = D + D exp -D 1+ D ln 1+ D

σ ε T

m

f n

v

σ3ε = ε + α exp -

2 σ

2

2V m1 1

V,M V,M

σ 3σ0 = + 2fq cosh - 1+ q f

σ 2σ

0

E

εf

Source: Diss-Abouridouane


Friction modelling for the FE cutting simulation

Thermal load on the tool-workpiece interface

1 primary shearing zone

2 secondary shearing zone of the face

3 seperative zone (stagnation point)

4 secondary shearing zone of the flank

5 preliminary deformation zone

workpiece structure

cut surface

turning tool

flank

rake face

shearing

plane chip

structure

2

vc

1

5

3

4

600

700 650

600

400

450

500

300 310

380 ºC

130

80 500

30

Workpiece

Chip

Tool

Workpiece material: Steel

Yield strength: kf = 850 N/mm2

Cutting material: HW-P20

Cutting speed: vc = 60 m/min

Uncut chip thickness: h = 0,32 mm

Rake angle: o= 10º

Temperature distribution on the contact zone

(by Kronenberg)



Deformation on the tool-workpiece interface

turning tool

shearing zone

0,1 mm






workpiece material: C53E

cutting edge material: HW-P30

cutting speed: vc = 100 m/min

cross-section area of cut: ap x f = 2 x 0,315 mm2

cut surface

workpiece structure

cut surface

turning tool

flank

rake face

shearing

plane chip

structure

2

vc

1

5

3

4



Mechanical load on the tool-workpiece interface






workpiece structure

cut surface

turning tool

flank

rake face

shearing

plane chip

structure

2

vc

1

5

3

4

Normal stress:

Shear stress:

Tool

by Oxley und Hatton

Contact zone


Coulomb friction model:

Shear friction model:

with

Transition from sliding friction (Coulomb) to

sticking friction (Shear):

Z.B.: Usui-Model

τR – Friction shear stress

N – Normal stress

k – Von Mises flow shear stress

kf – Von Mises flow stress

µ, m – Friction coefficients

kmR

NR


R

3

fkk

Orowan / Özel

Usiu

Shaw /

Wanheim und Bay

Reality

N

Coulomb friction

Shear friction

Reality

N

R

Sticking Sliding


Wear modelling for the FE cutting simulation

Wear typs on the tool cutting edge and wear mechanisms

Sliding mechanisms No sliding mechanisms

Abrasion Adhesion Delamination Diffusion Electrochemical Oxidation

Tool cutting

edge

Cutting edge

breakouts

Crater wear

Flank wear

Oxidation

Flank wear

Crater wear

Built-Up-Edge

Tool

Flank face

Rake

face

Workpiece

Chip


Tool wear modelling

tool life by Taylor: tool life by Hasting:

B

AT

v

k

c CvT

T = tool life

= temperature k, A, B = constants

Cv = T for vc = 1 m/min

empirical

tool wear model

physical

tool wear model

tool wear modelling

tool wear rate models tool life equations

model by Usui: model by Takeyama: model by Archard:

H

SFK

dt

dV

3

)T

C(

1chn

2

eCvσdt

dV

R

E

eDvGdt

dVc

dV/dt = wear volume per time

H = hardness

F = mechanical load

S = cutting path

K, C1, C2, G, D = constants

n = normal pressure

vch = sliding velocity

= temperature

Abrasion + Diffusion Adhesion

Adhesion /

Abrasion


FEM Software Solution for FEM simulation of the Cutting Process

MSC.Marc


Criteria for the evaluation of FE software

Source: SIMULIA, ANSYS, LSTC, TWS, SFTC, COMSOL

Criteria

Program ABAQUS ANSYS/ LS-DYNA AdvantEdge DEFORM COMSOL

Creation of geometries Creation of geometries

and import of CAD data

Import of CAD data

Creation of simple

geometries and

import of CAD data

Creation of simple

geometries and

import of CAD data

Creation of simple

geometries and import

of CAD data

Material catalogue No, has to be defined Yes, expandable Yes, wide Yes, new catalogue

importable

yes

Element type Every type Every type tetrahedron,

rectangle

tetrahedron, rectangle Every type

Time integration Implicit / Explicit Implicit / Explicit Explicit Implicit Implicit

Remeshing routine none none yes yes yes

use general general Cutting process Deforming process general

Influence on simulation

computation

High, by Python Possible, by Fortran no High, by Fortran High, by Matlab

parallelization possible possible possible possible possible

Usage at the WZL Eigenfrequency analysis,

elast. Tool behavior,

elasto-plastic component

behavior

no no Cutting simulation Thermo-elastic

deformation


Cutting process simulation

Turning Drilling Milling

Calculation of the thermo-mechanical tool-load-collective

for an ideal dimensioning of the tools‘

micro- and macrogeometry


Simulation of the chip flow (turning)

Material:

C45E+N

Cutting material:

HC P25

Insert:

CNMG120408

Insert geometry:

Cutting velocity.:

vc = 300 m/min

Feed:

f = 0,1 mm

Depth of cut:

ap = 1 mm

Dry cutting

Chip breaker FN Chip breaker RN

0 0 S r

6° -6 ° 95°-6°

90°

0 0 S r

6° -6 ° 95°-6°

90°


First Contact Start of Shearing Crack Initiation Gliding

End of Gliding New Segmentation

Mate

rial S

pe

ed / m

/min

0

12,5

25

37,5

50

62,5

75

90

Segmented Chip Simulation reveals periodic sticking zone

Start of Shearing Crack initiation

strain rate


Verification of the mechanical load

Cutting tool material: HC-P25

Workpiece material: C45E+N

CL: dry

Process: turning

Ff

Fp

Fc

200

600

1000

1400

f = 0.1 mm f = 0.2 mm

sim

ula

tio

n

exp

erim

en

t

1800

Ff

Fp

Fc

constant: vc = 350 m/min; ap = 3 mm

200

600

1000

1400

vc = 250 m/min vc = 350 m/min

sim

ula

tio

n

exp

erim

en

t Ff

Fp

Fc

Pro

cess forc

es F

i/ N

Ff Fp

Fc

constant: f = 0,1 mm; ap = 3 mm

200

600

1000

1400

ap = 1 mm ap = 3 mm

sim

ula

tio

n

exp

erim

en

t

Ff Fp

Fc Ff

Fp

Fc

constant: vc = 350 m/min; f = 0.1 mm

Pro

cess forc

es F

i/ N

Pro

cess forc

es F

i/ N


533

3 µm 6 µm

TiN Al2O3

TiN

6 µm 0

510

520

530

540

550

560

570

Ca

lcu

late

d t

em

pe

ratu

re a

t th

e

chip

bottom

sid

e T

Sp / °

C

heat conductivity:

HW: 100 W/(mK)

TiN: 26,7 W/(mK)

Al2O3: 7,5 W/(mK)

material: C45E+N

tensile strength: Rm = 610 N/mm²

557

539

509

539

heat capacity:

HW: 3,5 J/(cm³K)

TiN: 3,2 J/(cm³K)

Al2O3: 3,5 J/(cm³K)

HW: HW-K10/20

TiN

3 µm

TiN

6 µm

HW TiN

6 µm

Al2O3

6 µm

coating

thickness

Tsp

FE simulation of turning considering coating


FE-Based Calibration process for the tool wear model

Verschleißmarkenbreite über die Schnittzeit

16MnCr5 (einsatzgehärtet), Stegbreite = 1 mm, cBN bestückte Einstechplatte der Sorte N151.2-600-50E-G

Schnittgeschwindigkeit vc = 150, 200, 300 m/min und Vorschub f = 0,06 mm

0

20

40

60

80

100

120

0 5 10 15 20 25 30 35 40

Schnittzeit t [min]

Ve

rsc

hle

ißm

ark

en

bre

ite

VB

[µ

m]

vc = 250 m/min vc = 200 m/min vc = 150 m/min

Cutting time t

To

ol-w

ear

VB

Wear curve

C2

lg C1

1/T

lg{w

/(n

VS)}

lg

{w/(

nV

S)}

Regression analysis FE-analysis

Temperature

Normal-

tension

Sliding speed

dW/dt

Machining experiments

Determination of the

specific material

parameters C1 and C2

)T

C(

1chn

2

eCvσdt

dW

t = 1 min

t = 4 min t = 6 min

t = 10 min

Modeling











Outline


Technical Sensors in Metal Cutting

Measuring platform Rotating cutting force

dynamometer

Acceleration sensor Force measuring pin

Load ring Pyrometer Process remarks

vc

Cutting force

Ac

ce

lera

tio

n

Source: Kistler Instrumente AG


Temperature Sensor

Thermo-element

Resistance thermometers

Two color pyrometer

Infrared camera


3D Coordinate Measuring


1 mm

vc= 20 m/min

f = 0,3 mm

Wo

rkpie

ce

hold

er

vc

wo

rkp

iece

Features and Technical Data of the Test Bench

Shaft holder max. 32x32

Grooving / Parting Tool holders for orthogonal cutting (Inclination angle = 0°, tool edge angle = 0°)

Phantom v7.3 High speed video camera, LED Illumination


Advanced Experimental Setup: Orthogonal Cut on Broaching Machine

High speed external broaching machine:

– Type: Forst RASX 8x2200x600 M/CNC

– Max. force: 80 kN

– Power: 40 kW

– Max. cutting speed: 150 m/min

– Tool fixed und workpiece moved

– Optimal filming of the cutting zone

High speed camera:

– Type: Vision Research Phantom v7.3

– Frame rate: 6.688 fps by 800 x 600 pixel

500.000 fps by 32 x 16 pixel

High speed IR camera:

– Type: FLIR SC7600

– Frame rate: 100 fps by 640 x 512 pixel

800 fps by 160 x 128 pixel

– Measurement range: -20°C - 3000 °C (±1°C)

wo

rkp

iece

wo

rkp

iece h

old

er

IR camera

tool

HS camera

tool holder

tool

measurement platform

wo

rkp

iece High-Speed Filming

High-Speed Thermography

wo

rkp

iece h

old

er


Turning: Comparison of Simulation and Real Chip Flow

CNMG120408

Chip breaker NF

HC-P15

r = 95°

n = -6°

s = -6°

C45E+N

ap = 1,9 mm

f = 0,25 mm

vc = 200 m/min

dry

vc vf


.

Full agreement

Experiment Simulation

FE simulation of face milling operation


FE computation of mechanical tool load and chip form in drilling

0,0

1,0

2,0

3,0

Exp

eri

men

t

Sim

ula

tio

n

Torque

Exp

erim

en

t

Sim

ula

tion

0

100

200

300

400

Exp

eri

men

t

Sim

ula

tio

n

Feed force

[Nm] [N]

4% Deviation 7% Deviation

Simulation

Experiment

Cutting speed: vc = 35 m/min Workpiece: C45E+N

Feed: f = 0.18 mm Cutting tool material: HW-K20

Drill diameter: d = 8 mm Cutting edge radius: rß = 60 µm


FE computation of the cutting temperature in drilling

Cutting speed: vc = 35 m/min Workpiece: C45E+N

Feed: f = 0,012 * d Cutting tool material: HW-K20

Coolant: none Cutting edge radius: rn = 4 µm

d = 3 mm

0

100

200

300

400

1 3 8 10

diameter d [mm]

Te

mp

era

ture

at th

e

ma

jor

cu

ttin

g e

dg

e T

[°C

]

Experiment

Simulation


High Speed Thermography During Chip Formation (vC = 150 m/min)

h = 0.10 mm h = 0.50 mm

Tool:

Carbide, uncoated

Sharp (rß 5 µm)

Workpiece:

AISI 1045 normalized

3.5 x 50 x 200 mm

600

400

350

300

250

200

50

0

°C


Material and Friction Laws Validation:

Chip Formation (Orthogonal Cut, vC = 150 m/min, AISI 1045)

h = 0.4 mm h = 0.5 mm h = 0.3 mm

FE simulation Experiment FE simulation Experiment FE simulation Experiment

h = 0.2 mm h = 0.04 mm h = 0.02 mm

FE simulation Experiment FE simulation Experiment FE simulation Experiment


Material and Friction Laws Validation:

FE Cutting Simulation (vC = 150 m/min, h = 0.50 mm, DEFORM)

Plastic strain[ - ]

[MPa]Effective stress

[ C]

Temperature

[1/s]Strain rate


Development of 3D FE computation model for macro twist drilling:

d = 8 mm, homogeneous microstructure, Deform 3D

Workpiece

Twist drill

Twist drill CAD model

Gühring KG

d = 8 mm

rß = 0 µm

RT100U_5510

Constitutive material law (WZL)

m

rm

r

0

n

TT

TT1

ε

εlnC1εBAσ

Cutting parameters definition

Boundary conditions adjustment

Twist drill: Rigid with mesh

d = 8 mm and rß = 30 µm

Workpiece: Visco-plastic

D x H = 12 x 4 mm

with heat dissipation

100,000 3D-Tetrahedron

Contact: Coulomb friction

law (µ = 0.30), heat transfer

(Conduction & Convection)

Workpiece material: 27R, 45R, 60R

Tool material: HW

Cutting speed: 120 m/min

Feed rate: 0.25 mm/rev


FE model results: Chip formation, temperature, computation time: 1 day

45R, vc = 120 m/min, f = 0.25 mm, d = 8 mm, dry


FE-Simulation of the drill entrance: Computation time: 5 days



Check of the optimized FE model: Feed force and torque


0

250

500

750

1000

1250

1500

0 10 20 30 40 50 60 70 800

2

4

6

8

10

12

14

16

Drilling time t / ms

Fe

ed f

orc

e F

z /

N

Torq

ue

Mz /

NmFeed force

Torque

with entrance without entrance


0

1

2

3

4

5

6

7

Feed force Torque Feed force Torque Feed force Torque

Test

FE-Simulation

FE model validation: Feed force and torque (deviation less than 15%)

vc = 120 m/min, f = 0.25 mm, d = 8 mm, dry

27MnCr5 C45E C60

kN

Nm











Outline


What is the Optimization Problem?

Source:Papalambros

F(x1,x2,…,xn) Minimize (or maximize)

an objective „performance“ function:

taking into account the constraints: Gi(x1,x2,…,xn) = 0, i=1,2,…,p

Hj(x1,x2,…,xn) < 0, j=1,2,…,q

(x1,x2,…,xn) are the n system variables

Gi(x1,x2,…,xn) are the p equality constraints

Hj(x1,x2,…,xn) are the q inequality constraints


System Example: Cantilever Beam

System variables: F(t), U(t), Mb(t), V(t)

System parameters: h, b, L

System constants: E, ρ

L

F(t)

Steel (E, ρ)

h

h

b U(t), Mb(t), V(t)

System U(t) F(t)

System F(t) U(t)

System V(t) h, b, L

E, ρ

System Mb(t) F(t)

Mathematical model:

3

3

3

33

hbE

LF4

12

bhE3

FL

EI3

FLU


Integration of the Optimization in the FEM

Physical problem

Mathematical model

Numerical model

Change physical

problem

Improve mathematical

model

Refine analysis

Process improvement and optimization

Does answer

make sense?

Yes!

No!

FEM Optimization


Thank you for your attention

simulation techniques in manufacturing technology · 28. okt l 53c/101 ozhoga-maslovskaja forming...

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