基于激光拼焊技术的汽车B柱结构优化设计

Structure Design of Automotive B-Pillar Based on Tailor-Welded Blank Technology

利用激光拼焊技术对某轿车B柱进行结构材料一体化设计,在轻量化设计的前提下对其入侵位移和入侵速度进行控制以满足整车侧碰安全性能.根据C-NCAP碰撞法规建立该轿车侧碰有限元模型,并验证了模型的准确性.基于网格节点变形技术创建B柱参数化模型并定义3个结构设计变量和2个材料类型设计变量,以其质量、中部最大入侵位移和最大入侵速度为优化目标,以其上部和下部最大入侵位移和最大入侵速度为约束条件,结合径向基(RBF)近似模型和非支配遗传算法(NSGA-Ⅱ)对B柱结构进行多目标优化设计,获得Pareto优化前沿,并讨论妥协方案验证对B柱多目标优化设计的效果.

A tailor-welded blank technology was used to perform the integrated design of structure and material for B-pillar.To meet the collision performance,the intrusion displacement and invasion speed of B-pillar were controlled under lightweight design.Based on the C-NCAP,a finite element model of the side collision system was built and verified.A parametric model of Bpillar was built based on the mesh morphing technology.On the basis,three structural design variables and two material type design variables were defined.Then,setting the mass,maximum intrusion displacement and maximum invasion speed of the middle of B-pillar as the multiobjectives,the maximum intrusion displacement and maximum invasion speed of the upper and lower of B-pillar as constrains,the radial basis function（RBF）surrogate model and nondominated sorting genetic algorithm（NSGA-Ⅱ）were applied to perform the multi-objective optimization design of B-pillar.The Pareto front was obtained and some compromise solutions were discussed to verify the effectiveness of structure design of B-pillar.