汽车前保险杠碰撞过程动力学仿真与分析

Dynamic Simulation and Analysis of Vehicle Bumper Collision

前保险杠是汽车正碰主要吸能部件,在很大程度上决定了汽车的耐撞性与安全性。针对汽车碰撞过程中前保险杠的大变形和非线性接触问题,建立了某款国产轿车前保险杠(包括:保险杠、吸能盒和纵梁)与刚性墙碰撞有限元模型。采用分段线性塑性材料本构模型和显式动力学有限元法对其碰撞过程进行动态仿真,获得了保险杠、吸能盒和纵梁的变形情况、能量变化情况以及碰撞力曲线。仿真结果与实验结果吻合良好,从而验证了有限元模型正确性。结果表明,槽型诱导结构比盒型诱导结构更容易诱导纵梁产生褶皱变形,且碰撞力曲线随纵梁的褶皱变形产生波动。

The front bumper is the main energy-absorbing component in the frontal impact, which, to a large extent, determines the crashworthiness and safety of a vehicle. Based on the large deformation and nonlinear contact of front bumper in the process of vehicle collision, the finite element model of front bumper（including bumper, energy-absorbing box and longitudinal beam） colliding with the rigid wall were established. The piecewise linear plastic material constitutive model and explicit dynamic finite element method were adopted to dynamically simulate the process of collision and the deformation, energy changes and impact force curve of bumper, energy-absorbing box and longitudinal beam were obtained. The simulation results are in good agreement with the experimental results, which verifies the correctness of the finite element model. The research results show that the inducing structure of slot type is easier to induce the fold deformation of longitudinal beam than that of the inducing structure of box type, and the impact force curve fluctuates with the fold deformation of longitudinal beam.