基于侧碰的梯度性能热成形B柱抗撞性能优化

Optimization of Crashworthiness for Tailored Hot Forming B-pillar Based on Side Impact

基于动力显式有限元算法,以侧碰过程中B柱的吸能量-EA和最大侵入量Dmax为评价指标,对比分析热成形强度梯度分布及厚度梯度分布对零件抗撞性能的影响。进一步,基于径向基函数建立梯度性能热成形B柱的侧碰代理模型,并采用NSGAII遗传算法分别对两种梯度性能B柱(强度、厚度)进行多目标优化设计,获得了梯度性能热成形B柱帕朗特前沿解集。结果表明:优化后的梯度强度及梯度厚度热成形B柱的抗撞性能相较于原始工况有显著提高,且梯度厚度B柱比梯度强度B柱具有更大的可设计空间,结合多目标优化结果可进一步提高车身零部件的综合抗撞性能。

The crashworthiness of B-pillar with tailored properties in vehicle side impact is researched based on dynamic explicit finite element method by taking the energy absorption and maximum intrusion of B-pillar as evaluation index. The effect of gradient strength distribution and gradient thickness distribution against collision performance is analyzed and their performance is compared to uniform strength B-pillar. In addition, radial basis function is applied to build the surrogate model of B-pillar and by which the multi-objective optimization design of B-pillar with tailored properties is carried out then. The results show that the performance of B-pillar with tailored properties are improved remarkably after optimization design, which proves that multi-objective optimization can further improve the comprehensive collision performance of vehicle structure.