基于PA6/SGF复合材料的CBS结构仿真与拓扑优化

CBS Structure Simulation and Topology Optimization Based on PA6/SGF Composites

摘要: 近年来，交通事故造成了数万人死亡，在不降低车身耐撞性前提下减少车身质量以提高汽车的续航里程成为了一个关键问题。为此，引入了复合材料车身加强件(Composite Body Solutions, CBS)结构，本文研究对象是一个由短玻纤增强尼龙6 (Polyamide 6/Short Glass Fibre, PA6/SGF)复合材料注塑成型的T型车身接头。首先，对PA6/SGF复合材料进行了4种影响因素的全矩阵拉伸实验，获取材料力学性能参数并分析规律。其次，对B柱上接头CBS进行结构建模与落锤验证。最后，基于变密度法对B柱上接头CBS结构进行拓扑优化，又采用NSGA-II算法进行多目标优化，优化结果显示最大入侵量和碰撞力峰值分别下降了14.5%和59.28%，实现了在不提高质量的前提下大幅提高耐撞性的目标。对于提高整车结构耐撞性能具有一定指导意义。

Abstract: In recent years, traffic accidents have caused tens of thousands of deaths, and reducing body mass to improve the range of cars without reducing the crashworthiness of the car has become a key is-sue. To this end, the Composite Body Solutions (CBS) structure is introduced, and the object of this study is a T-shaped body joint injection molded from Polyamide 6/Short Glass Fibre (PA6/SGF) composites material. Firstly, the full matrix tensile test of four influencing factors was carried out on the PA6/SGF composites, and the mechanical properties of the material were obtained and the rules were analyzed. Secondly, the structural modeling and drop weight verification of the CBS joint on the B-pillar were carried out. Finally, based on the variable density method, the topology of the CBS structure of the B-pillar upper joint is optimized, and the NSGA-II algorithm is used for mul-ti-objective optimization, and the optimization results show that the maximum intrusion amount and the peak collision force decrease by 14.5% and 59.28%, respectively, which achieves the goal of greatly improving the crashworthiness without improving the quality. It has certain guiding signif-icance for improving the crashworthiness of the whole vehicle structure.