应用正交试验法汽车B柱轻量化设计分析

B柱是车身重要的承载结构件,对侧面碰撞安全具有重要影响,同时B柱也是轻量化设计的重要单元。根据B柱的结构特点和在车辆侧面碰撞中的结构形态,搭建B柱侧面碰撞仿真分析模型;根据分析结果和零件的可制造性分析,基于正交试验法对B柱的材料和厚度进行设计,并根据乘员的相对位置对激光拼焊的焊缝进行设计;根据侧面碰撞的侵入量和侵入速度对比,选出最优激光拼焊设计方案;基于侧面碰撞分析模型,对轻量化设计前后B柱的安全性进行对比分析。结果可知:随拼焊线向底部移动,危险区域的最大减薄率并不是线性增减,在可选取范围内将焊缝位置确定为距离底端380mm的位置;B柱选择拼焊板结构,下部材料为DP780,厚度为1.8mm,上部材料为DP590,厚度为1.6mm;采用激光拼焊结构的B柱重量减轻23.1%,各位置测量点的侵入量最高减少18.6%(D4位置),满足结构耐撞性的要求。

Lightweight Design Analysis of Automobile B-Pillar Based on Orthogonal Test Method

The B-pillar is an important load-bearing structural part of the vehicle body,which has an important influence on the safety of the side collision.At the same time,the B-pillar is also an important unit of lightweight design.According to the structural characteristics of the B-pillar and the structural form in the side collision of the vehicle,the simulation analysis model of the B-pillar side impact is built.According to the analysis results and the manufacturability analysis of the parts,the material and thickness of the B-pillar are designed based on the orthogonal test method,and the weld of the laser tailor-welded weld is designed according to the relative position of the occupant.According to the comparative analysis of the intrusion amount and intrusion speed of the side collision,the optimal laser tailor welding design scheme is selected.Safety comparative analysis between B-pillars before and after lightweight design is taken based on lateral collision analysis model.As a result,it is known that the maximum thinning rate of the dangerous area is not linearly increased or decreased as the tailored wire moves to the bottom,and the position of the weld is determined to be 380mm from the bottom end within the selectable range.B-pillar selects the tailor welded plate structure,the lower material is DP780,the thickness is 1.8mm,the upper material is DP590,and the thickness is 1.6mm.The weight of the B-pillar using the laser tailor welded structure is reduced by 23.1%,and the intrusion amount of each measurement point is reduced by 18.6%(D4 position),which satisfies the requirements of structural crashworthiness;provides an important reference for such design.