基于碰撞安全性汽车前防撞梁总成轻量化设计

前防撞总成是汽车正面碰撞时最重要的承载件,起到吸收能量和保护乘员的作用,也是轻量化设计的重要结构。根据前防撞梁总成的结构特点,选取横梁和吸能盒作为研究对象,选择材料、厚度、截面形式等方面进行轻量化方案设计,选择最大加速度、侵入量、能量吸收和单位质量承载力等作为优化设计目标,对不同结构的零件进行优化设计。并对优化设计前后总成的性能进行对比分析,选择正面100%重叠工况和40%偏置碰撞工况进行对比分析,获取加速度、承载力等变化曲线。结果可知:优化设计后横梁材料DP980D+Z,厚度1.3mm;吸能盒的截面形式为十字形、无设计倾角,材料则选择高强钢DP780D+Z,厚度为1.6mm;轻量化后总成的加速度、侵入量、最大承载力均无明显变化,变化趋势基本一致;最大侵入量满足设计要求,最大承载力与实际值偏差为2.3%,满足要求;表明总成轻量化设计方案的可行性,为实际应用提供参考依据。

Lightweight Design of the Vehicle Bumper Beam System Based on Crash Safety

The front anti-collision assembly is the most important carrier when the car is in a head-on collision.It plays the role of absorbing energy and protecting the occupants,and is also an important structure for lightweight design.According to the structural characteristics of the front anti-collision beam assembly,select the beam and the energy absorbing box as the research object.Selecting material,thickness,and section form for structural lightweight design.Select the maximum acceleration,intrusion amount,energy absorption and unit mass bearing capacity as the optimization design target;optimize the design of parts with different structures.And compare and analyze the performance of the assembly before and after optimization,comparative analysis of front 100%overlap and 40%offset collision.Obtain the changing curve of acceleration and bearing capacity.The results show that the optimized beam material is DP980D+Z and the thickness is 1.3mm.The section shape of the energy absorbing box is cross-section and has no design inclination.The material is made of high strength steel DP780D+Z with a thickness of 1.6mm.After the lightweighting,the acceleration,maximum invasion and maximum bearing capacity of the assembly do not change significantly,and the trend of change is basically the same.The maximum intrusion meets the design requirements,and the maximum bearing capacity and actual value deviation is 2.3%.The deviation between maximum bearing capacity and actual value is 2.3%which meet requirements.It shows the feasibility of the lightweight design of the assembly,and provides reference for practical application.