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IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Hybrid Finite Element Model For Side Impact Simulations
Guide
Dr. T. JAGADEESH ,
PG Co-coordinator,
Bangalore Institute of Technology ,
Bangalore.
Project Carried out in
BANGALORE INDTITUTE OF TECHNOLOGY
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Regulatory Requirement :
It is mandatory for all passenger vehicles get Homologation (confirm officially) Certification of that country before launching any vehicles in that country.
United States : National Highway Traffic Safety Administration (NHTSA) as per FMVSS
Europe : Economic commission for Europe (ECE) India : Society of indian Automotive Manufactures (SIAMS) & Automotive research of India
Crash Tests :
Frontal Impact ( FMVSS 208 , ECE R94, Euro NCAP )
Side impact ( FMVSS214, IIHS, ECE R95, Euro NCAP )
Rear Impact ( FMVSS 301, ECE R32 )
Roll over etc..
INTRODUCTION :
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Side Impact Details :
Un struck side Struck side
Struck side :
Experiences large Elasto-plastic Deformations in Side Impact.
Unstruck side (including front and Rear_end) :
Experiences gross rigid body motion with elastic deformations.
Front End
Rear End
Dodge Neon model taken from : NHTSA (www- nrd.nhtsa.gov.com)
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Upper body beams
Under body beams
Side body
Elasto - Plastic deformation zones in side impact simulations.
LH Side_Doors with Door trims
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Why to Represent the Unstruck side in detail ?
How to Reduce the Computation time ?
How to decrease the Model Size so that Computation space can be reduced ?
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Literature Survey :
Frontal impact Reduced Order model
- Tomohiko ,Masanori et all, Kamal, etc
Side impact Struck side reduced order model
- Trella et all , Heon Young Kim, J.E Tomassoni, etc
Rear End Hybrid model :
- Lchiro Hagiwara, etc
Side impact Un-struck side representation by Hybrid element model is Not addressed in many studies.
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
The project will be directed towards
• Developing a efficient strategy to build hybrid finite element vehicle model for side impact analysis by retaining the elasto-plastic deformation zones with shell elements and the elastic/ undeformed zones with one dimensiona/Reduced ordered elements.
• Reducing Model size and Computation time without sacrificing model fidelity.
Objective of the Project :
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Project Challenges
Side impact itself is a very Complex scenario
- No Crush space Availability,
- Less time for Restraint system for activation,
- Occupant is very close to the Impact Zone.
-Lateral velocity can vary along the length of the car hence mass distribution should be proper.
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Dodge Neon Baseline Simulation:
Assumptions:
1. Dodge Neon Model is Considered as a Base model and converted as a Side impact set up.
2. Unit System used in the Model.
Rigid_Barrier_Details
Mass of Rigid _Barrier 1300 kg ( 1.3 tone)
Velocity of Rigid Barrier 13.91(30 mph) 13911 mm/second
UnitsLength milimeterTime SecondMass TonneForce Newton
3 Instead of Moving Deformable Barrier (MDB) Rigid Barrier is considered for worst case scenario.
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Baseline_Side_impact Setup :
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Deformed Shape at 90 milisecond
0 milisecond
Dodge Neon Side impact Set up With Rigid Barrier.
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Base_Model_Details.
Nodes 283880
Elements 275993
No. Of Parts 342
Materials 336
Properties 336
Groups 63
No of Joint 12
Airbags 4
Rigid walls 5
Mass elements 336
Cross sections 18
Mass Details: Kg
Structural Mass 782.5
Lumped mass 534.34
Total_vehicle_mass 1316.85
Dodge_ Neon side impact base model details.
Computation Time : 64.1 Hours for 90 millisecond
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Mean_strain_rate_Distribution for Baseline Model
IP/Beam and Dash board
Bar 1
Bar 2
Bar 3
B Piller
Side structure + Dog leg
Roof_bows
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Side impact Mechanics. Collapse modes of main structure.
(Courtesy: 1999-01-3185 (SAE) Heon Young, Kangwon Nation University)
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Courtecy :CarBodydesign.com
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Matrics Parameters for Correlation :
Global Energy Plot
B-piller Intrusion Plot
Latera Y - Velocity of the Vehicle at unstruck side (Rocker)
Global Energy Plot B-piller Intrusion Plot
Y - Velocity
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
ITERATION - 1: Lumped mass approach
Right Hand Side (Unstruck Side) of Full vehicle is replaced with a Lumped mass.
CG of the Mass Element is maintained same as that of the RH side CG.
Mass element is Connected with a Nodal Rigid Body to Vehicle.
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
CG_NID 2907144 Mass : 471.243 kg
X Y Z
3308.58 -65.9835 523.412
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Lumped mass approach Results
Global Energy Plot
B-piller Intrusion PlotY - Velocity
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Results Comparison With Baseline:Iteration -1Baseline
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Results Discussion :
1. Results are matching till 35 milisecond as the deformation is in the struck side.
2. Due to the lack of Primary load carrying members complete geometry, Deformation stops at Struck side to mid of the vehicle.
3. Lumped mass behavior is different than the Structure deformation hence results show deviations later on.
4. Lateral Velovity Shows the difference because Absence of Structural member to transfer the Load.
5. Vehicle intrusion matches with the Baseline as the Overall Mass and Struck side structure behavious in the same manner as in baseline.
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
ITERATION 2: Right hand side rigid material approach
Excluding the High deformation zone parts , Remaining parts in the Right hand side are Assumed rigid material by moving them all into one part.
Connection of this Rigid part is maintained with the body as it is.
Mass and CG of the Rigidized portion of the vehicle is maintained the same by adjusting the density of the Rigid Component.
All parts connecting to this Rigid part are taken care as a Xtra_Node option.
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Right hand side rigid material:Setup
Rigid Material
12
3B Pillar
IP/Beam and Dashboard
Roof bows
Highly deformable members are excluded from Rigid mat assignment.
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Global Energy Plot
B-piller Intrusion Plot
Y - Velocity
Right hand side rigid material: Rsults
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Results Comparison With Baseline: RH Rigid materialBaselineGlobal Energy Plot
B-piller Intrusion Plot
Y - Velocity
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Results Discussion :
1. Global Energy , Lateral velocity, Intrusion Plot’s matches with the base line with in the acceptable range.
2. This simulations requires extra precaution to exclude Primary load carrying members from assigning them a rigid material.
3. Finding out the Rigid material Center of gravity and tuning the mass of the rigid material as per the actual mass is one more activity needs to be performed.
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
ITERATION – 3 : SUB SYSTEM LUMPED MASS
Representing the sub systems with Lumped masses with out effecting the vehicle characteristics.
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
18.83 Kg
Door hinges
Door latch
SUB SYSTEM LUMPED MASS :Right hand side door replacement
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
18.31 kg
Right hand side door replacement with proper connections
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Sub system lumped mass approach :Door replacement
Baseline
Right hand side door replacement Results
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
11.52 Kg
SUB SYSTEM LUMPED MASS: Hood Assembly Replacement
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
286.5 kg
SUB SYSTEM LUMPED MASS: Engine Assembly Replacement
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
14.06 kg
9.99 kg
SUB SYSTEM LUMPED MASS: Front and Rear Wind Shield Replacement
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
17.73 Kg
Battery_assembly
SUB SYSTEM LUMPED MASS: Battery Assembly Replacement
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
7.60 kg
SUB SYSTEM LUMPED MASS: Radiator Assembly Replacement
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
SUB SYSTEM LUMPED MASS : intermediate results
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
12.29 kg
Front _ Bumper_Assembly
SUB SYSTEM LUMPED MASS : Front bumper replacement
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
2.56 Kg
2.56 Kg
SUB SYSTEM LUMPED MASS : Fender replacement
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
8.95 Kg
SUB SYSTEM LUMPED MASS : Lift gate(Rear hatch) replacement
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
19.88 kg
SUB SYSTEM LUMPED MASS : Rear bumper replacement
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
Sub systems with lumped mass final Model
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
SUB SYSTEM LUMPED MASS : Results comparisonSub system lumped mass approach
Baseline
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
z Case studies Assembly_NameNo of elements Nodes
Solving_time (Hours )
1 Base_line_run 275993 283862 6.41E+01
2 Case_Study-1 RH_NRB_With_Lumped_mass 141847 150284 2.89E+01
3Case_Study_
2 RH_Rigid_Mat_assigment. 132042 139780 3.60E+01
4Case_Study_
3Sub_system_with respective Lumped masses at their CG..
Doors_with_mass 250251 257467 4.44E+01
Door_and_Hood_mass 241805 248829 4.10E+01
Door_and_Hood_windshield_mass 240739 247774 3.88E+01
Door_and_Hood_windshield_powertrain 238543 245913 3.95E+01
Door_and_Hood_windshield_powertrain_battery 237784 245149 3.81E+01
Door_and_Hood_windshield_powertrain_battery_CRFM 234800 243258 3.86E+01
Door_and_Hood_windshield_powertrain_battery_CRFM_Frt_bump 226924 235719 3.63E+01
Door_and_Hood_windshield_powertrain_battery_CRFMM_Frt_bump_fender 224146 232822 3.62E+01
Door_and_Hood_windshield_powertrain_battery_CRFMM_Frt_bump_fender_lift_gate 218387 227009 3.31E+01
Door_and_Hood_windshield_power_train_battery_CRFMM_Frt_bump_fender_lift_gate_rear_bump 213534 222178 3.18E+01
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
CONCLUSION :
Computation Time
Results correlation
Computation reduction
Baseline 64.1 100% 3.58 GBLumped mass 28.1 60% 1.1 GBRigid material 36 95% 1.8 GBSub system lumped mass 31.8 90% 2.2 GB
Computation Time
Results correlation
Computation reduction
Baseline 64.1 100% 3.58 GBLumped mass 28.1 60% 1.1 GBRigid material 36 95% 1.8 GBSub system lumped mass 31.8 90% 2.2 GB
Computation Time
Results correlation
Computation reduction
Overall Rating
Baseline 64.1 100% 4.58 GB -
Lumped mass 28.1 60% 1.1 GB PoorRigid material 36 95% 1.8 GB GoodSub system lumped mass 31.8 90% 2.2 GB Excellent
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
FUTURE SCOPE OF THE PROJECT
Courtacy: Heon Young Kim, Sang Bum Kim, Kangwon Nation University
Reduced Hybrid model for side impact simulations where Struck and un struck side are represented by reduced order elements and which correlates with the experimental results.
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S
References :
1. T. J. Trella, R. R. Samaha, E. J. Smith, ”The use of Advanced Analytical Techniques in Side Impact Crashworthiness Research”Fifteenth International Conference on the Enhanced Safety of Vehicles, Melbourne, Australia, May 13-16, 1996. 2. T. Ariyoshi, “Development of a Beam Element Model for an Analysis of a Motor Vehicle Rear End Crash”,SAE International Congress and Exposition, Detroit, Michigan, USA, Feb26-Mar2, 1990. 3. M.Tani, R.I.Emori, “A Study no Automobile Crashworthiness”, Automotive Engineering Congress and Exposition, Detroit, Michigan, USA, Jan12-16, 1970. 4. M. M. Kamal, “Analysis and Simulation of Vehicle to Barrier Impact”, Automotive Engineering Congress and Exposition, Detroit, Michigan, USA, Feb27-Mar3, 1978. 5. H-S Kim, S-Y Kang, In-H Lee, S-H Park, D-C Han, “Vehicle Frontal Crashworthiness Analysis by Simplified Structure Modeling using Nonlinear Spring and Beam Elements”, Int. J. Crashworthiness, Vol2, No1,pp107-117,1997. 6. Heon Young Kim, Sang Bum Kim,Sang Soon Kwon,Sung Kook Oh, Chang Sup Ahn, “A Study on The Hybrid Finite Element Modeling for Side Impact Simulation” ( Copyright © 1999 Society of Automotive Engineers, Inc. ) 7. lchiro Hagiwara, Yasuo Sasakura, Tadashi Nakagawa and Yoshihiro KajioNissan Motor Co., Ltd. International Congress and ExpositionCobo Hall, Detroit, Michigan February 23-27, 1981
IV SEMESTER M.TECHM/C DESIGN
SEPT 2005 to Oct 2010
BANGALORE INSTITUTE OF TECHNOLOGY
UMESH G S