基于侧面碰撞工况下B柱抗弯性能优化设计

Optimization Design on Bending Performance of B-pillar Based on the Side Impact Condition

基于侧碰工况,选取B柱薄弱截面,将其等效简化为单帽型薄壁梁.建立三点弯曲试验模型,研究单帽梁的抗弯性能.选取截面长宽比和外板厚度为设计变量,加载力峰值和比吸能为优化指标,轻量化和抗弯稳定性为约束条件.利用最优拉丁超立方设计采取30组样本点,建立优化目标的响应面模型,通过NCGA遗传算法进行多目标优化.优化后最大加载力下降7.87%,比吸能提高14.4%,同时加载力波动度下降10.5%,质量下降8.97%.抗弯性能得到显著提高.

Based on the side impact condition,the weak section of B-pillar was selected and simplified equivalently as the single-hat thin-walled beam.The three point bending test model was established to study the bending performance of single-hat beam.The cross-sectional aspect ratio and external plate thickness were selected as the design variables,the peak loading force and specific energy absorption were determined as the optimization indexes,and the lightweight and bending stability were considered as the constraint conditions.Using the design of the optimal Latin hypercube,30 groups of sample points were taken to establish the response surface model of optimization objectives,and the multi-objective optimization was carried out by the NCGA genetic algorithm.After the optimization,the maximum loading force is reduced by 7.87%,the energy absorption energy increased by 14.4%,the undulation of load-carrying capacity decreased by 10.5%,and the mass down by 8.97%.The bending performance is improved significantly.