| 1. PrefaceToday, with the development of the automotive industry, especially the rapid development of the highway, people has realized that it is impossible to avoid traffic accident entirely due to the driver himself, the road conditions, the weather, the vehicle technique condition and so on. It is meaningful how to keep occupant form injury when impact happened, and to reduce the damage which arose by the accident, and also to improve the safety of vehicle.It shows from statistic data that side impact probabilities are 27% among all kinds of crash accidents. When occupants'injuries and property losses considered, probabilities will reach a relatively high level, near to those of frontal impacts. That is because car side structure is very weak, and there is only door structure and a space of tens of centimeters and so little buffering room between inside and outside. When impacted in lateral direction, it has no enough crush room to absorb crash energy just like frontal and rear parts. And also, head, thorax, abdomen, pelvis always hurt seriously, what's more, head will especially always be exposed and impact objects outside which will cause fatal injuries.Occupant side impact restraint system has been one of the passive safety research focuses. Computer simulation is already one important method besides real impact and sled rest. It can not only reduce crash tests but save development cost. Also it can guide design direction in concept design stage and cut short development period.Among side impact restraint system researches inflatable curtain is a focus. IC appears a few years ago, and it's used specially to protect head during side impact. Because of its superiority its application has become a trend and it has already been applied in many intermediate and senior cars.This paper is with the topic set cooperrate the our itme with the incorporated company of safe system"the car on the IC and the chest airbag mold piece of development"for foundation launch.discusses several problems in IC development and design base on CAE2. MAIN CONTENTSThe paper shows and summary a flow chart of CAE-based side curtain airbag design procedure2.1 IC CAD Model SetupThis paper according to CAE-based side curtain airbag design procedure build the IC CAD model with MADYMO6.2 version developed by TNO aided with other software. amony the CAD model the paper focal point on the with diffuser tube IC CAD models built. The diffuser tube design is critical to the performance of the side curtain airbag systems. So to bilut the diffuser tube is very important to the side curtain airbag systems desige. IC CAD model with diffuser tube use of multi-chamber model establishment the model that the diffuser tube puts into the bag.and definition export the animation files, max and min size files to discuss the model validation2.2 IC CAE Model Setupaccording to CAE-based side curtain airbag design procedure.with the CAE analysis.Before any physical airbag was sewn and tested, preliminary CAE analysis was performed to provide directional guidance for the airbag design.The typical side curtain airbag CAE analysis includes but is not limited to,1. cushion coverage zone review.2. cushion volume evaluation3. cushion press distributed analysis4. deployment timing reviewThe commonly used uniform pressure airbag models serve the purpose in most cases. But for analysis such as cushion deployment timing evaluation, Computational Fluid Dynamics (CFD) integrated airbag models have to be employed because the uniform pressure airbag models are not able to simulate the deployment time difference among various parts of the airbag cushion. In this paper, most types of the abovementioned analysis are integrated into a typical side curtain airbag design cycle. Both uniform pressure airbag models and CFD integrated airbag models are used complementarily to help the side curtain airbag design. The CAE-based side curtain airbag design procedure helps to reduce the material cost and time duration of the airbag design process.Its geometry is determined through cover zone design folded in FOLDER module. It's placed in a cover after dynamic relaxation, which is the initial state.If a cushion design passes all these simulation checkpoints, prototypes can be built and tested. The tests are mainly used to confirm the simulation results.The design evolves based on CAE simulations rather than on numerous tests.2.3 Pole side impact sled test Model Setup and The system integrationPole side impact sled test model contains four parts: structure, dummy, seat and rigid pole. IC is coupled with baseline through contact and support.Because of the carbody transforms to influence the dummy sport to thus influence the injury value of dummy head,so The emulation that the carbody transform is important for the simulations. In the design development stage of the IC has no a structure model, Put forward to the carbody to collide the base line to around transform an establishment to have another the body bodywork model with the rigid pillar just, Schedule to also righteousness just the acceleration of the body to imitates the bodywork that the trolley experiment to transform the circumstance.3. SIGNIFICANCEThe CAE-based side curtain airbag design procedure discussed in this paper shows great potential to reduce the material cost and time duration of the airbag design process. Besides the cost savings, the CAE-based approach also provides the following benefits compared with the traditional test based approach:1. The test based approach is a trial and error process per se. With CAE models, especially the CFD simulations, deeper understanding and insights to the physics of the design problems, which are very hard to obtain through physical tests, can be achieved. In other words, CAE helps to understand"how the design works and why it works".2. The test based approach often ends up with a working design. But it is not always the optimal design. With a CAE-based approach, Design of Experiments (DOE) and other numerical optimization tools can be used to optimize a design.3. The CAE experience learned from previous designs can be easily transferred to new products.The significance of this paper is as follows:First, this paper utilizes MADYMO6.2 deeply, and masters a general progress in the research of side impact occupant restraint system which summarizes experience for the next work;Second, This paper is with the topic set cooperrate the our itme with the incorporated company of safe system"the car on the IC and the chest airbag mold piece of development"for foundation launch.so the contents of study even has the realistic meaningThird, his paper brings up a flow chart of CAE-based side curtain airbag design procedure and base on computer simmulation and with Pole side impact sled test to verification, and makes simulation more accurate.
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