A Study of High Refinement Simulation Prediction on the CAB Development for FMVSS226 Ejection Mitigation Performance
2022-01-0922
03/29/2022
- Event
- Content
- In the side impact crash accident, the curtain airbag (CAB) plays a significant role in the occupant head protection. With the increasing of the rollover accidents, the CAB development is requested to be able to protect the occupant head throughout the whole rollover accident, and to ensure that the occupant head is not partially or totally ejected from the vehicle. NHTSA released the FMVSS226 Standard in 2011, defined the requirements for ejection mitigation systems, which limits the linear travel of headform by 100mm. In China regulations, there are similar requirements starting in 2021. The difference is that it can be replaced by meeting the pressure holding requirements of 6s (up to 50% of the average pressure of 40-70ms). Therefore, on the basis of the existing airbag design, adding the rollover protection function becomes a new challenge for the airbag development. During the development of the curtain airbag, the cushion design, inflator type, and the fold pattern, all have an important influence on the unfolding direction, positioning time and the airbag internal pressure, and then significantly affect the occupant protection performance. In order to reduce the cost and shorten the development time, it is necessary to predict the process of cushion deployment and the internal pressure of the airbag with high refinement, and based on it to evaluate the FMVS226 Ejection Mitigation performance. In this paper, a set of complete simulation development process is proposed and developed with FEA simulation method. Based on the step by step simulation and test validation of the Tank test, fabric material mechanical properties test, airbag folding, airbag static deployment test, drop tower validation and the final FMVSS226 performance validation, after high-precision simulation results are obtained in each step of CAB development, the discrepancy of final simulation results of the FMVSS226 headform offset compared with the one of test is less than 2%. It shows that the final simulation results have a very high accuracy to predict the test results of FMVSS226 ejection mitigation performance, and the simulation process proposed in this paper effectively guides the whole airbag development process.
- Citation
- Shan, J., Xue, L., and Wang, C., "A Study of High Refinement Simulation Prediction on the CAB Development for FMVSS226 Ejection Mitigation Performance," SAE Technical Paper 2022-01-0922, 2022, .