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5th% hybrid III dummy in out of position

By Joshua Wells,2014-05-21 14:56
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5th% hybrid III dummy in out of position

    thThe Comparison Study of 5%tile Hybrid III Dummy in Out

    of Position Computer Simulation by MADYMO/Ls-Dyna

    Coupling 1111 Dongjuan Zhang, Jason Lim, Ke Ding, Feifei Wang1TRW Automotive Research & Development (Shanghai) Co., Ltd Copyright ? 2009 TNO Automotive China

    female facet dummy developed by TNO automotive ABSTRACT was used in this simulation model and the results were

    compared with LSTC rigid dummy. In this paper, a comparison study between th MADYMO & Ls-Dyna 5percentile hybrid III dummy in drive Out-of-Position (Oop) computer simulation

    was conducted. The study was started with Ls-Dyna

    code and followed by MADYMO/Ls-Dyna coupling

    method. A finite element model (FEM) of a steering

    wheel system (SWS) and driver airbag module (DAB) with star folding cushion was modelled to study the th injury criteria of a 5Fig.1 The 5percentile hybrid III drive Oop th percentile hybrid III female simulations process dummy in Oop simulation. DAB linear impactor simulation, DAB static deployment simulation for 2. Cushion Folding airbag hybrid method & airbag particle method were

    modelled and correlated before the Oop simulation. In

    the Oop simulation, the FEM folding cushion was

    modelled by airbag particle method which could show

    better agreement in term of cushion deployment

    kinematics behaviours compared with control volume

    method via airbag hybrid method.

    The 5th percentile hybrid III female facet dummy

    developed by TNO automotive was used in this

    simulation model and the simulation results were

    compared with LSTC rigid dummy.

1. Introduction Before folding

     FMVSS208 Notice of Proposed Rule Making from

    NHTSA requires manufacturers to improve occupant [1]performance criteria . This includes performance

    requirements to ensure that the airbags do not cause

    unreasonable risk of serious injuries to Oop occupants. th This paper paid more attentions to the 5percentile

    hybrid III female dummy Oop computer simulation.

    The finite element model of a star folding cushion with

    the DAB and SWS was modelled with Ls-Dyna

    software. Before the DAB Oop simulation, DAB

    folding, DAB linear impact and DAB static deployment (airbag hybrid & airbag particle) were After folding simulated. The process was shown in Fig. 1. In the Oop Fig.2 The cushion before and after folding simulation model, the finite element method (FEM) of

    folded cushion was deployed by airbag particle method Cushion folding mode is significant for Oop injury which could show better agreement in term of cushion evaluation. For example, tuck-in folding and star deployment kinematics and behaviours compared to folding are considered good folding modes for driver control volume method. The 5side Oop. In this paper, a standard 45 litres of DAB th percentile hybrid III

    1

    thth5 MADYMO China Users Meeting, Hangzhou China, November 5-6 , 2009

    with star folding mode was used. The cushion before

    and after folding was shown in Fig. 2.

    3. DAB linear impact Impactor distance correlation results The DAB linear impactor simulation was used to

    correlate cushion permeability and porosity at different

    impact velocity. The control volume method (airbag

    hybrid) was used to simulation the cushion deployment.

    Fig.3 and Fig.4 showed the DAB linear impactor

    simulation & correlation results. Fig. 4 correlation

    results showed that the function used for cushion

    permeability in the simulation model could well fulfil the physical characteristics of DAB linear impact Force-distance correlation results physical test. Fig.4 DAB linear impact correlation between

    4. DAB Static deployment simulation simulation and test

    The DAB FEM static deployment simulation was

    essential before the driver Oop simulation. It used to

    correlation cover opening time, air pressure, filling

    time, DAB component level performance. The

    correlated function and parameter of cushion

    permeability in DAB linear impact (airbag hybrid)

    were used in static deployment simulation model to

    ensure the static deployment simulation model for

    airbag hybrid could well correlated.

    The airbag particle (the corpuscular method) was

    based on the kinetic molecular theory which was

    developed by Lars Olovsson[2]. Fig.5 showed the

    comparison results between the airbag particle and the

    airbag hybrid (control volume method) at cushion different deployment time. Fig.6 was the pressure Fig.3 DAB linear impact simulation results curve comparison between airbag particle and airbag

    hybrid. From comparison, although the pressure curves

    difference was very little, the cushion deployment state

    showed large difference. And the DAB static

    deployment by airbag particle method showed good

    agreement in dealing with cushion deployment

    kinematics and characteristics.

    Acceleration Correlation results

     Airbag particle Airbag hybrid

    At time 5ms

    Velocity Correlation results

     Airbag particle Airbag hybrid

    At time 8ms

    5

     Airbag particle Airbag hybrid

    At time 13ms

     At time 5ms

     Airbag particle Airbag hybrid

    At time 20ms

    At time 10ms

     Airbag particle Airbag hybrid

     At time 30ms

    Fig. 5 DAB static deployment simulation

    comparison

    At time 20ms

Fig.6 the pressure curve comparison between airbag

    particle and airbag hybrid

    th5. 5 Percentile Driver Oop Simulation

    3

    thth5 MADYMO China Users Meeting, Hangzhou China, November 5-6 , 2009

     Fig.8 X direction acceleration comparison

    At time 30ms

     At time 40msFig.9 chest deflection comparison

    thFig.7 the 5 percentile Oop MADYMO/Ls-Dyna

    coupling simulation results

    thFig. 7 was the 5 percentile hybrid III driver Oop

    simulation results at different cushion deployment time

    by MADYMO/Ls-Dyna coupling. The finite element

    model of a star folding cushion with the DAB and

    th SWS was modelled by LSDYNA software. The 5

    percentile female facet hybrid III dummy developed by

    TNO automotive was used in simulation model. The

    cushion was deployed by airbag particle method. Fig.8,

    Fig.9, Fig.10, Fig.11 and Fig.12 shows the comparison

    results of X direction acceleration, chest deflection,

    chest acceleration, neck X direction shear force and neck My moment respectively between MADYMO

    facet dummy and Ls-Dyna rigid dummy. Fig.10 chest acceleration comparison

    5

    Acknowledge

    Thank Jason for advice and suggestion during driver

    out of position simulation. Thank Ke Ding and Feifei

    Wang for kindly help when using MADYMO software.

    Reference

    1. Federal Safety Standard #208, Crashworthiness

    Occupant protection.

    2. Lars Olovsson, Corpuscular Method for Airbag

    Deployment Simulation in LSDYNA, ISBN 978-

    82-997587-0-3, May, 2007 Fig.11 Neck X direction shear force comparison Contact

    Dongjuan Zhang, Simulation engineering in TRW

    Shanghai. Telephone: 61209186, Mobile phone:

    13482591534

     Fig. 12 Neck My-moment comparison

    6. Conclusion

     th In this paper, the 5percentile Hybrid III driver Oop computer simulation using MADYMO/Ls-Dyna coupling method was studied. The simulation includes DAB folding, DAB linear impact, DAB static deployment (airbag hybrid & airbag particle), and DAB Oop simulation. From the simulation results comparison with LSDYNA rigid dummy, following conclusions can be drawn: 1) The comparison of both results before 0.0125s showed reasonable agreement. 2) For Ls-Dyna Rigid dummy after 0.0125s showed unstable in its output and disagreement in the results.

    3) As for the simulation acceleration and injuries

    results by MYDYMO/Ls-Dyna coupling are

    reasonable compared to Ls-Dyna rigid dummy.

    5

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