基于SFE CONCEPT的某平台改款车型车身结构轻量化设计

Lightweight design of body structure of a platform’s modified vehicle based on SFE CONCEPT

首先,利用SFE CONCEPT建立某平台老款车型白车身的参数化模型,通过将参数化模型的白车身刚度和模态分析结果与传统有限元模型分析结果进行对比,验证了参数化模型的精确性。其次,按照改款车型的最新造型对参数化白车身模型进行更新,得到改款后的车身刚度和模态性能。接着,对改款车型的上车身进行拓扑优化,得到新的传力路径设计。然后,对拓扑优化后的上车身,选取关键位置处的截面,考虑刚度和模态两个学科,进行截面的灵敏度分析,基于灵敏度分析结果筛选变量进行多学科优化。最后,以上车身非安全件的料厚作为设计变量,考虑车身刚度性能进行料厚灵敏度分析,综合考虑碰撞、NVH等性能提出料厚优化方案。通过拓扑优化、截面优化和料厚优化,在满足性能目标的前提下,车身减重约17.5 kg,取得了显著的轻量化效果。

In this article, firstly, the parametric model is set up on a platform’s old white body by means of SFE CONCEPT. The accuracy of the parametric model is verified by comparing the results of stiffness and modal analysis with those obtained from the traditional finite-element analysis. Secondly, the parametric model is updated according to the latest model of the modified vehicle;its stiffness and modal performance are obtained. Then, topology optimization of the upper body of the modified model is carried out, and a new design of force transmission path is worked out. For the upper body after topology optimization, the section at the key position is selected, and it is subject to sensitivity analysis, with the two disciplines of stiffness and modal taken into consideration. Based on the results of sensitivity analysis, the variables are selected for multi-disciplinary optimization. Finally, with material thickness of the upper body’s non-safety parts as the design variables, the sensitivity analysis is carried out with the body’s stiffness performance taken into account. The optimization schemes of material thickness are proposed with collision, NVH and other performance taken into consideration. Through optimization of topology, section and material thickness, the body weight reduces by about 17.5 kg, achieving a higher standard of lightweight, while reaching the performance requirements.