Kartik Srinivas NL-FEA-of Engineering Components
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Transcript of 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
Confidential © Kartik Srinivas
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
Confidential © Kartik Srinivas
MATERIAL EXTRACTION FOR TIRE FEA
Confidential © Kartik Srinivas
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
Confidential © Kartik Srinivas
TIRE ANALYSIS RESULTS
Likely locations for Interlaminar shear
Confidential © Kartik Srinivas
Elastomer Spring
Part-2
Elastomer Spring
Part-2
DEVELOPMENT OF A RUBBER SPRING
Part-1Part-1
Confidential © Kartik Srinivas
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.
Confidential © Kartik Srinivas
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
Stiffness Results for Design # 3
2.5
3
3.5
Lo
ad
, L
bf
Stiffness Results for Design # 3
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
Confidential © Kartik Srinivas
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
Confidential © Kartik Srinivas
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.
Confidential © Kartik Srinivas
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
Confidential © Kartik Srinivas
PERFORMANCE PREDICTION
STRESS AND STRAIN DISTRIBUTION IN THE DIAPHRAGM AT MAXIMUM DEFORMATION
Confidential © Kartik Srinivas
DIAPHRAGM PROTOTYPE
PROTOTYPE INSTALLED AND TESTED AT BHABHA ATOMIC RESEARCH CENTRE (BARC), MUMBAI
Confidential © Kartik Srinivas
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
Confidential © Kartik Srinivas
DEFORMATION PLOTS FOR SPINAL DISC
Deformation Under Pre-compression followed by Flexion Loading
Deformation Under Pre-compression followed by Extension Loading
Confidential © Kartik Srinivas
DEFORMATION PLOTS FOR SPINAL DISC
Deformation Under Pre-compression followed by Torsion Loading
Deformation Under Pre-compression followed by Bending
Confidential © Kartik Srinivas
STIFFNESS PLOTS FOR SPINAL DISC
Confidential © Kartik Srinivas
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
Confidential © Kartik Srinivas
Deformation at end of Crimping Step
DEFORMED SHAPE OF STENT
Deformation at end of Expansion Step
Confidential © Kartik Srinivas
MOLECULAR BEARING ASSEMBLY
Confidential © Kartik Srinivas
Axial Compression
Axial Results & FEA Model Verification
Fixed
2 Step Analysis:
1st step = Pre-compression andInstallation
2nd step = Axial loading
Confidential © Kartik Srinivas
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
Confidential © Kartik Srinivas
Comparison of FEA and Experiment Results
Confidential © Kartik Srinivas
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°
Confidential © Kartik Srinivas
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
Confidential © Kartik Srinivas
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
Confidential © Kartik Srinivas