基于等效静态载荷法的车身碰撞拓扑优化

将约束释放作为边界条件引入基于等效静态载荷法的拓扑优化中,以应变能作为整车刚度的评价指标,引入相对位移作为部件柔度的评价指标.对比研究了整车正碰工况下采用约束释放和单点约束作为碰撞分析模型的拓扑优化的异同以及不同优化目标对优化结果的影响.研究结果表明:采用约束释放作为边界条件的优化结果更集中于碰撞发生位置的结构优化,而采用单点约束作为边界条件的结果更倾向于在约束处分布材料;相对位移最小可以作为优化目标,而最大化相对位移最好转化为约束条件再优化.

Topology Optimization of Automotive Body Crashworthiness Design with Equivalent Static Loads Method

The crashworthiness topology optimization of body in white (BIW) under frontal impact loading was carried out by using the equivalent static loads method (ESL). Inertia relief was introduced as boundary conditions; strain energy was adopted as strain energy and relative displacement was employed as the compliance index of the components and parts. A series of comparative studies were executed to discuss the effects of different boundary conditions and various optimization objectives. The results show that if an inertia relief is used as a boundary condition, the ESL based topology optimization results have a tendency to distribute more material on the impact occurred position, while the single point constraint (SPC) boundary conditions tend to concentrate more materials on the contrived SPC restrained positions. In addition, minimizing relative displacements is suitable for the ESL based topology optimization, but maximizing relative displacements should be transformed into constraints to perform the optimization.