kartik srinivas nl-fea-of engineering components

• Education – B.E. Mechanical Eng. L.D. College of Engineering -1998– M.S. Mechanical Eng. Wright State University - 2001– Polymer Eng. Course Certifications Univ. of Akron – 2002-2003– CNC Machinist Certificate Akron Machining Institute - 2004

• Professional Experience

KARTIK SRINIVAS

• Professional Experience

– Mechanical Testing of Engineering Materials: MTS®, Instron® and Proprietary Servo-hydraulic and Electro-mechanical Load frames.

– Performance Characterization of Elastomeric Products.– Finite Element Analysis of Engineering Products and Components

– Automotive (Under the hood, suspension components, tires, etc.).– Biomedical (Spinal, knee, and hip implants, stents etc.)– Aerospace (Static and dynamic analysis for honeycomb structures etc.)

– Durability Testing and Lifetime Prediction using Accelerated Test Conditions.

Confidential © Kartik Srinivas

ENGINE MOUNT DESIGN-ANALYSIS

DEFORMED MOUNT UNDER VARIOUS LOADING CONDITIONS


Stiffness Plot for Z-Direction Deformation

300

400

500

600

700

800

Lo

ad

, N

ENGINE MOUNT FEA RESULTS VERIFICATION

0

100

200

0 2 4 6 8 10 12

Deflection, mm

Test # 1 Test # 2 FEA Results

Confidential

Comparison of Experimental and FEA Results

© Kartik Srinivas

ENGINE MOUNT FEA RESULTS VERIFICATIONStiffness Plot for X-Direction Deformation

1500

2000

2500

3000

3500

Lo

ad,

N

0

500

1000

0 2 4 6 8 10 12 14Defection, mm

Test # 1 Test # 2 FEA Results

Confidential

Comparison of Experimental and FEA Results© Kartik Srinivas

FEA TIRE MODELS WITH BELTS FOR INTERLAMINAR SHEAR


MATERIAL EXTRACTION FOR TIRE FEA


LOAD-DEFLECTION RESULTS

Load Vs. Deflection on GW 245/75R16

800

1000

1200

1400L

oad

, L

bf

Expt.

FEA

Comparison of Experimental and FEA Results

0

200

400

600

0 0.2 0.4 0.6 0.8 1 1.2

Displacement, in

Lo

ad,

Lb

f

FEA


TIRE ANALYSIS RESULTS

Likely locations for Interlaminar shear


Elastomer Spring

Part-2

Elastomer Spring

Part-2

DEVELOPMENT OF A RUBBER SPRING

Part-1Part-1


DESIGN REQUIREMENTS

1) Application: Reciprocating Compressors used in Oilfields.

2) Axial Stiffness: Medium Force Application (15 lbf/in)

3) Strain: Maximum Strain Levels at or Lower than 80%.

4) Stress: Maximum Stress Levels at or Lower than 2000 psi.

5) Resilience: High Resilience with Low Hysteresis and Excellent

Tear Properties

6) Ambient Conditions: Able to Withstand High Temperature

and Oilfield Conditions.


CANDIDATE DESIGNS FOR RUBBER SPRING

Part-2

Part-1

Elastomer partPart-2

Part-1

Elastomer part

aa

Part-2 Elastomer partPart-2 Elastomer part

Design # 1 FEA Model Design # 2 FEA Model

Design # 3 FEA Model Confidential © Kartik Srinivas

High Stress Locations

Stiffness Results for Design # 1

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 0.02 0.04 0.06 0.08 0.1 0.12Displacement, in

Fo

rce

, lb

f

FEA Results

Stress-Strain Distribution and Load-Deflection in Design # 1Confidential © Kartik Srinivas

High Stress Locations

Locations of Stress greater than 2000.0 psi and Strains greater than 200 % in the ModelLocations of Stress greater than 2000.0 psi and Strains greater than 200 % in the Model

Stress and Strain Distribution in Design # 2Confidential © Kartik Srinivas

Locations of Stress greater than 2000.0 psi and Strains greater than 200 % in the ModelLocations of Stress greater than 2000.0 psi and Strains greater than 200 % in the Model

Stress and Strain Distribution in Design # 3Confidential © Kartik Srinivas


2.5

3

3.5

Lo

ad

, L

bf


2.5

3

3.5

Lo

ad

, L

bf

FINAL SPRING DESIGN WITH DESIRED STIFFNESS CHARACTERISTICS

0

0.5

1

1.5

2

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16Displacement, in

Lo

ad

, L

bf

FEA Results

0

0.5

1

1.5

2

0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16Displacement, in

Lo

ad

, L

bf

FEA Results

Deformed shape of Design-3 and Stiffness Plot


No. FKM HNBR

Tensile Strength at Room Temperature1 16.0 Mpa 31.0 Mpa

Ultimate Elongation (%)

2 120.0 (120 – 250 %)225.0 (225 - 750 %)

– High strength mechanical properties

Both Therban and FEPM

FKM AND HNBR COMPARISON SUMMARY

3 Good explosive decompression characteristicsBoth Therban and FEPM retain highest strength in explosive decompression

situations4 Weak strength at high operating

temperaturesCan be formulated as per

requirements.5 Low tear resistance Excellent tear resistance

6 Limited resistance to steam, hot water, methanol, and other highly polar fluids.

Suitable for use in methanol and

methanol/hydrocarbon mixtures if correct

Acrylonitrile level is used


No. Design Summary of FEA Results

1.Design # 1 (Conceptual

Design)

Linear load-deflection relationship, stiffness below requirements

High stress concentrations Maximum stress generated at the bond

areas with part-2

SUMMARY OF FEA RESULTS

areas with part-2

2. Design # 2

Part shows a slight non-linearity in force-deflection response

Stiffness is higher than required Maximum stress and strain values are

very high.

3. Design # 3

Slight non-linearity in force-deflection response

Stiffness is within the requirements Maximum stress and strain values

well within the failure limits.


Design Development and Analysis of Front Mounts for HD Truck

Application

Front Mounts

Sample Stress Analysis Results for Full System Model

Representative Stress Analysis Results

Displacement direction

Stress Analysis Results

Displacement direction

Representative Final Design for Front Mount

Design Requirements:1. Restrict excessive deformation

in Y, and Z direction, specificallyin tensile mode.

2. Should be able to confirmto the geometrical space.

3. Low Stress and Strainin the design.in the design.

Sample Stress-Strain Distribution in Tension

Stress Distribution in Compression

Stress Distribution in Steel

Stress Distribution in Rubber

Sample Stress-Strain Distribution in Shear

Stress Distribution in Steel

Stress Distribution in Rubber

DUAL MATERIAL DIAPHRAGM DEVELOPMENT

SKETCH OF THE DESIGN IDEA

CAD MODELConfidential © Kartik Srinivas

FEA MODEL OF THE DIAPHRAGM

DIAPHRAGM LOCATED IN PRESSURE CHAMBER ASSEMBLY


PERFORMANCE PREDICTION

STRESS AND STRAIN DISTRIBUTION IN THE DIAPHRAGM AT MAXIMUM DEFORMATION


DIAPHRAGM PROTOTYPE

PROTOTYPE INSTALLED AND TESTED AT BHABHA ATOMIC RESEARCH CENTRE (BARC), MUMBAI


DESIGN DEVELOPMENT AND FEA OF SPINAL DISC

Material: Polyurethane,

Simulated Deformation Modes:1) Compression, Shear2) Pre-compression followed by Flexion3) Pre-compression followed by Extension4) Pre-compression followed by Bending5) Pre-compression followed by Torsion


DEFORMATION PLOTS FOR SPINAL DISC

Deformation Under Pre-compression followed by Flexion Loading

Deformation Under Pre-compression followed by Extension Loading


DEFORMATION PLOTS FOR SPINAL DISC

Deformation Under Pre-compression followed by Torsion Loading

Deformation Under Pre-compression followed by Bending


STIFFNESS PLOTS FOR SPINAL DISC


COMPOSITE MATERIAL FEA MODEL AND ANALYSIS PROCEDURE VERIFICATION

Verification of ASTM D 3763 Test Procedure

a

bc

a

bc

Comparison of FEA Vs. Experimental Results

-100

0

100

200

300

400

500

600

700

800

900

0 0.002 0.004 0.006 0.008 0.01 0.012

Time, Sec

Lo

ad,

Lb

f

Experimental Results FEA Results

Verification of ASTM D 3763 Test Procedure

Simulated Deformation Modes:

1. Model Crimping deformation.2. Model Expansion deformation.3. Identify “Hotspots” and suggest parameters for design change.4. Provide feedback on deformation pattern and stress-strain distribution.

FINITE ELEMENT ANALYSIS OF CORONARY STENT

Material

Elastic Modulus (GPa) Yield Strength (MPa) Tensile Strength (MPa) Density (g/cm3)

Ti6Al4V 110 795 860 4.5

Ta 190 138 207 16.6

316L SS 196 205 515 7.85

CoCrMo 210 450 655 8.3

Comparison of Material Properties for Stent ApplicationConfidential © Kartik Srinivas

FEA MODEL OF STENT

Compression

Expansion

Stent

Simulated Stent Deformation


Deformation at end of Crimping Step

DEFORMED SHAPE OF STENT

Deformation at end of Expansion Step


MOLECULAR BEARING ASSEMBLY


Axial Compression

Axial Results & FEA Model Verification

Fixed

2 Step Analysis:

1st step = Pre-compression andInstallation

2nd step = Axial loading


Comparison of FEA and Experiment Results

Comparison of Load-Deflection Results from the Two-step AnalysisConfidential © Kartik Srinivas

Radial Compression

Radial Deformation Analysis

Fixed

2 Step Analysis:

1st step = Pre-compression andInstallation

2nd step = Radial loadingConfidential © Kartik Srinivas

Radial Deformation Analysis

Stress Distribution in the Rubber Under Radial Load of 200KN


Comparison of FEA and Experiment Results


Torsional Deformation Analysis

Stress Distribution in the Rubber Under Torsional Deformation of 9°Confidential © Kartik Srinivas

Strain Distribution in the Rubber Under Torsional Deformation of 9°


Material Evaluation Product Design and AnalysisMaterial Characterization and Durability Testing

EXPERIENCE BASED CONSULTINGIN MULTIDISCIPLINARY PRODUCT DEVELOPMENT

AND MATERIAL TESTING

Failure Analysis Patent Development Feedback and Optimization of Rubber

Compounds


Srinivas, K., Material Characterization And CAE For Non-Metallic Materials & Manufacturing Processes, SAE Symposium on CAE Applications for Automotive Structures, Detroit, November 2005.

Srinivas, K., and Pannikottu, A., Material Characterization and FEA of a Novel Compression Stress Relaxation Method to Evaluate Materials for Sealing Applications at the 28th Annual Dayton-Cincinnati Aerospace Science Symposium, March 2003.

PUBLICATIONS

Cornelius, K. C., and Srinivas, K., Isentropic Compressible Flow for Non-Ideal Gas Model for a Venturi, ASME Journal of Fluids Engineering, Feb 2004.

Srinivas, K., and Pannikottu, A., Material Characterization and Finite Element Analysis of High Performance Tires, International Rubber Expo and Conference, Mumbai, March 2005.

Srinivas, K., and Dharaiya, D., Material And Rheological Characterization For Rapid Prototyping Of Elastomers Components, American Chemical Society, Rubber Division, 170th Technical Meeting, Cincinnati, October 2006


kartik srinivas nl-fea-of engineering components

Documents