Abstract: The rear end bending of front side member will lead to front collapse deformation of side member, larger dash panel intrusion, larger B pillar peak acceleration. In order to study the safety performance of a sport utility vehicle (SUV) under frontal collision, the finite element model of the vehicle frontal collision is established based on LS-DYNA commercial finite element software. The simulation results show that the bending deformation at the rear end of the front side member is the root cause of the large intrusion of the dash panel into the passenger compartment.Therefore, the structure and thickness for front side member and A pillar are optimized. The results show that the optimized scheme can effectively reduce the intrusion of the dash panel and the peak acceleration of the B pillar, and improve the safety and crashworthiness of the vehicle.

Key words: Frontal collision; Acceleration; Front side member; Intrusion; Frontal collision structure of SUV; Optimization analysis

摘要： 前纵梁后端弯折将会导致纵梁前端压溃变形、前围板侵入量较大、B 柱加速度峰值较 大，为研究某运动型多用途汽车（SUV）正面碰撞下的安全性能，基于 LS-DYNA 商用有限 元软件，建立整车正面碰撞有限元模型，仿真结果显示，前纵梁后端折弯变形是造成前围板 向乘员舱侵入较大的根本原因。因此，对前纵梁和 A 柱的结构和厚度进行优化。结果表明， 优化方案可以有效降低前围板的侵入量以及 B 柱加速度峰值，改善车辆的安全性和耐撞性。

关键词: 正面碰撞；加速度；前纵梁；侵入量；SUV 前碰结构；优化分析