Analysis And Optimization Of Occupant Injury Factors In Car Side Impact

Chinese traffic accidents statistics show that side impact is the most frequent accident type in vehicle accidents in recent years, and it has caused a lot of death, injuries and property damages. So the side impact and injury mechanism during the collision should be specifically studied. It is of great significance to improve side impact safety performance, occupant protection and traffic safety.First a side impact finite element model was developed with the software of Hypermesh. Then the LS-DYNA software was used to do the simulation. The effectiveness of the side impact finite element model was validated by comparing the simulation results with the results from real vehicle collision tests.Series of side impact simulations were conducted with the Orthogonal Design of Experiment. Four factors including the distance between the abdomen and interior handrail, the stiffness of door interior components, the stiffness of B pillar and the stiffness of the push block were studied to reveal their influence on occupant injuries. Results show that within a certain range, the comprehensive occupant injury will increase when the distance between the abdomen and interior handrail increases or the stiffness of B pillar increases or the stiffness of door interior components decreases. And the stiffness of the push block has little effect on occupant injuries in this model.A comprehensive evaluation index named Weighted Injury Criterion for Side Impact (WICSI) was proposed. In order to decrease WICSI, structural parametric optimization was conducted through regression analysis. Results show that when the distance between the abdomen and interior handrail is180mm, the stiffness of door interior components is25%of the original stiffness and the stiffness of B pillar is140%of the original stiffness, the minimum WICSI could be obtained. Also an objective function C-WICSI was proposed according to the C-NCAP score, and the same method was used to do the optimization. Results show that when the distance between the abdomen and interior handrail is180mm, the stiffness of door interior components is200%of the original stiffness and the stiffness of B pillar is140%of the original stiffness, the score of C-NCAP will be the highest.A method of strengthening the vehicle side structure stiffness and improving the interior structure was used to improve the vehicle side impact safety performance, and results show that the dummy injuries have been effectively improved.The results of this study may be useful in designing and optimizing the structure for side impact.