Computational models of Q dummy family Ines Lehmann, Heiko Johannsen (VFSB) Robert Kant, Christian Kleessen (Humanetics) Protection of children hld in cars, December 2 3, 2010, Munich Fahrzeugsicherheit Berlin e.v.
Content Computer aided d engineering i and Q model dldevelopment (Car) industry requirements for dummy models Q child model development Q child model validation Q child model application Summary Fahrzeugsicherheit Berlin e.v. 2
Fahrzeugsicherheit Berlin e.v. COMPUTER-AIDED ENGINEERING AND Q MODEL DEVELOPMENT 3
CAE Computer aided engineering (CAE) is the broad usage of computer Software to aid in engineering tasks Benefits: Early and better analysis of design problems Optimization of design problem Shorten design time and reduce costs Fahrzeugsicherheit Berlin e.v. 4
Bottlenecks Current bottlenecks for broad use of CAE in child safety domain Physical testing costs are relatively low No urgent need for OEM s Availability of Child Restraint System (CRS) models Limited experience at CRS industry Availability of models of the test procedures Availability of high quality dummy models Fahrzeugsicherheit Berlin e.v. 5
Expected developments Introduction of Q dummies increases testing costs Meeting future requirements is getting harder Euro NCAP is likely promoting older children Carrestraintsystem restraint system isgetting more importantfor child safety rating Fahrzeugsicherheit Berlin e.v. 6
Q modeling gprojects TUB: Q0 (2002...2006) Humanetics in house: Q3, Q3s (2006..2007) Casper project Humanetics & VFSB: Q1, Q1½, Q6 (2009..2010) Consortium: Q6 (2010 2013) 7 OEM s, Humanetics, TUB, VFSB, Simulia Codes: LS DYNA, PAM CRASH, ABAQUS ( > RADIOSS) Fahrzeugsicherheit Berlin e.v. 7
Other child models Crabi 12 months for FMVSS213 and 208 H303 and H306 for FMVSS 208 Fahrzeugsicherheit Berlin e.v. 8
Fahrzeugsicherheit Berlin e.v. CAR INDUSTRY REQUIREMENTS FOR DUMMY MODELS 9
Car industry requirements General: Harmonisation of hardware (Denton and FTSS) Models must represent the latest hardware (or maybe the hardware level of the customer) Correct implementation of the hardware are Geometry, mass and inertia Correct material properties (e.g., separation vinyl and foam) Implementation of all sensors (required and optional) Close collaboration between manufacturer of hardware and developer of models Knowledge about the manufacturing process Source: Dr. -Ing. Christian Gehre Partnership for dummy technology and biomechanics Automotive CAE Grand Challenge 2009 Fahrzeugsicherheit Berlin e.v. 10
Car industry requirements Technical: Time step of approx. 1 microsecond (dummies) without mass scaling Same geometry, mesh, joint angles for all codes (if possible) Numerically robust High level of predictability Detailed report of the validation process No need to use highly detailed models in general Support: Quick response time Regular updates and improvements Source: Dr. -Ing. Christian Gehre Partnership for dummy technology and biomechanics Automotive CAE Grand Challenge 2009 Fahrzeugsicherheit Berlin e.v. 11
Development and validation example Source: Dr. -Ing. Christian Gehre Partnership for dummy technology and biomechanics Automotive CAE Grand Challenge 2009 Fahrzeugsicherheit Berlin e.v. 12
Fahrzeugsicherheit Berlin e.v. Q CHILD MODEL DEVELOPMENT 13
Mesh development Source data for geometry and mesh Drawings CAD models Scans Q6 clavicle model verification: CAD versus FE mesh Fahrzeugsicherheit Berlin e.v. 14
Component Models - Q6 Rib Cage Molding Shoulder Retainer Ring Clavicle Skin Thoracic Spine Fahrzeugsicherheit Berlin e.v. 15
Models Q1 and Q 1½ Q1 Q1.5 Fahrzeugsicherheit Berlin e.v. 16
Statistics Q1½ Item Total Number Part/Section/Material 139 Nodes 28,736 Elements: total 43,797 Beam 109 Shell 19,585 Solid 24,039 Spring 61 Accelerometer 3 Joint 9 Contact surface 2 Curves & Table 5 Fahrzeugsicherheit Berlin e.v. 17
Material model development Material model development Quasi static tension andcompression Dynamic stress relaxation Strain rate compression Material tests (Q6) Head Skin/ Rib Cage Vinyl Skin /Upper Extremities Vinyl Skin/ Lower Extremities Vinyl Skin # of tests Neck Shield Foam 12 Multiple l strain rates at high h strain rate Jacket 12 covering the relevant loading spectrum Abdomen Foam 12 Neck Rubber 9 Shoulder Rubber 9 Lumbar Rubber 9 Pelvis Flesh 9 Head Skull 3 Clavicle 3 Rib Cage 6 Arm/Leg Hyperlast 9 Arm/Leg Bones 3 9 Neck Rubber Head Skin Total 105 Under development eop e Fahrzeugsicherheit Berlin e.v. 18
Fahrzeugsicherheit Berlin e.v. Q CHILD MODEL VALIDATION 19
Mass validation Head Head front 2.605 kg 2.605 kg Head rear 0.360 kg 0.36 kg Acc. mount 0.150 kg 0.150 kg Upper neck load cell replacement 0.150 kg 0.150 kg Fahrzeugsicherheit Berlin e.v. 20
Performance validation Head drop tests frontal Headdroptests drop lateral Neck pendulum tests Frontal Neck pendulum tests lateral Lumbar pendulum tests frontal Lumbar pendulum tests lateral Full dummy: Thorax impact tests frontal Full dummy: Thorax impact tests lateral Full dummy: overload impact test to check model stability Fahrzeugsicherheit Berlin e.v. 21
Certification Q 1½ 55 ±2 Head Rigid plate Test Test FEA v1.0beta Fahrzeugsicherheit Berlin e.v. 22
Certification Q 1½ Neck Frontal Test Test FEA v1.0beta Fahrzeugsicherheit Berlin e.v. 23
Certification Q 1½ Neck Lateral Test Test FEA v1.0beta Fahrzeugsicherheit Berlin e.v. 24
Certification Q 1½ Lumbar spine Frontal Test Test Test FEA v1.0beta Fahrzeugsicherheit Berlin e.v. 25
Certification Q 1½ Lumbar spine Lateral Test Test Test FEA v1.0beta Fahrzeugsicherheit Berlin e.v. 26
Certification Q 1½ Chest frontal - Speed 4.3 m/s Test Test Test FEA v1.0beta Fahrzeugsicherheit Berlin e.v. 27
Robustness check Q 1½ Rigid wall test speed 8.0 m/s Time=10ms Time=20ms Time=30ms Time=40ms Fahrzeugsicherheit Berlin e.v. 28
Validation size Q6 Q6 - tests Maximum Number of unique load cases Certification 11 Component 30 Sled 6 Under development in Q6 consortium project Fahrzeugsicherheit Berlin e.v. 29
Design of new Q6 tests Target data Pre simulation of validation test Courtesy of Adam Opel GmbH Current Q6 consortium task Fahrzeugsicherheit Berlin e.v. 30
Fahrzeugsicherheit Berlin e.v. Q CHILD MODEL DEVELOPMENT - APPLICATION 31
Application with Q0 frontal impact sled test Video Rearward facing baby seat with inlay Initial velocity: 13,88 m/s Limitations: CRS model not completely validated Dr. -Ing. Christian Gehre Development of a model of the new-born child dummy Q0 VDI, Reihe 12, Nr. 660 Fahrzeugsicherheit Berlin e.v. 32
Application with Q1.5 lateral impact sled test Rearward facing baby seat New GRSP IG CRS SI procedure Dummy readings within reasonable range CRS model not validated for lateral impact Test bench and impactor not completely validated Fahrzeugsicherheit Berlin e.v. 33
Application with Q1 accident reconstruction - video 1 YO in the rear left in FF CRS Child died from AIS 6 neck and AIS 5 head injuries Dummy readings within expected range CRS model not validated and CRS motion based on test accelerometer readings Fahrzeugsicherheit Berlin e.v. 34
Fahrzeugsicherheit Berlin e.v. SUMMARY 35
Summary For the introduction of CAE methods in the development process the following ingredients are necessary: Dummy models Product models Models of test environment Models of the Q0, Q1, Q1½, Q3, Q3s and Q6 have been developed Further investment is needed in CRS and environment models to achieve predictive models Fahrzeugsicherheit Berlin e.v. 36
Summary Q6 models are being further developed and extensively validated in a 3 year consortium project to develop CAE and hardware related knowledge and target fully reliable simulation. Partnerships between Humanetics and ESI/Altair/Simulia/DYNAmore facilitate rapid model development in PAM CRASH, RADIOSS, ABAQUS and LS DYNA at customer request Fahrzeugsicherheit Berlin e.v. 37
Acknowledgements Parts of the work presented has been co funded by the European Commission within the 7 Frame Work Programme CASPER project Grant Agreement no. 218564 www.childincarsafety.eu Fahrzeugsicherheit Berlin e.v. 38
Fahrzeugsicherheit Berlin e.v. THANKS! 39