纯电动SUV正面25%偏置碰撞仿真和优化

Simulation and Optimization of Frontal 25%Offset Collision for Pure Electric SUV

为研究某款纯电动SUV在正面小重叠碰撞下的安全性能,根据美国高速公路安全保险协会发布的测试规程,应用ANSA软件建立纯电动SUV正面25%偏置碰撞模型,利用LS-DYNA显式求解软件进行了计算。通过HyperView后处理软件分析了整车加速度、前围板最大侵入量、关键部件变形和吸能情况,发现该车型碰撞力有效传递路径为上纵梁传递到A柱,轮胎通过悬架系统传递到中地板边梁和门槛梁,而关键吸能部件(吸能盒和前纵梁)没有成为有效的碰撞力传递路径;乘员舱相关部件(A柱、A柱上边梁及中地板边梁等)刚度不足,该车型乘员舱变形严重。针对该车型在正面25%偏置碰撞试验中乘员舱变形严重的问题,从改善碰撞力传递路径和采用轻型铝合金材料以提高乘员舱刚度两个方面进行了优化。结果表明:整车碰撞安全性得到有效提高,乘员舱侵入量明显减小,前围板最大侵入量由246.59 mm减小到151.29 mm,降低了38.65%,结构评级由“差”提升到“良好”。针对提高乘员舱刚度后整车加速度峰值过大的问题,进行了L9(34)正交试验分析,得到了在前围板最大侵入量由151.29 mm降低到146.49 mm的前提下,整车加速度最大峰值由55.86g降低到44.77g的最优组合方案。

In order to study the safety performance of a type of pure electric SUV under small frontal overlap collision,according to the test regulation issued by IIHS,a frontal 25%offset collision model of the pure electric SUV is established by using ANSA software,and the calculation is performed by LS-DYNA explicit solution software.The acceleration of the vehicle,the maximum intrusion of the front panel,the deformation and the energy absorption of key components are analyzed by HyperView post-processing software.It is found that the effective transmission path of the collision force of the vehicle is from the upper longitudinal beam to the A-pillar,and from the tire to the mid-floor side beam and sill beam through suspension system,while the key energy-absorbing components(energy absorbing box and front longitudinal beam)have not become the effective transmission path of collision force.The stiffnesses of the relevant components in the passenger compartment(A-pillar and its upper beam,mid-floor side beam,etc.)are insufficient,the passenger compartment of the vehicle is seriously deformed.In view of the serious deformation of the passenger compartment in the frontal 25%offset collision test,the optimization is conducted from the aspects of improving the collision force transmission path and using light aluminum alloy materials to improve the stiffness of the passenger compartment.The result shows that the collision safety of the vehicle is effectively improved,the intrusion of the passenger compartment is significantly reduced,the maximum intrusion of the front panel is reduced from 246.59 mm to 151.29 mm,a decrease of 38.65%,and the structural rating is upgraded from“poor”to“good”.The L9(34)orthogonal test analysis is performed to solve the excessive vehicle peak acceleration after increasing the stiffness of the passenger compartment,and the optimal combination scheme is obtained,i.e.,under the premise that the maximum intrusion of the front panel is reduced from 151.29 mm to 146.49 mm,the maximum peak acceleration of the vehicle can be reduced from 55.86g to 44.77g.