车身结构中焊点布置的分区拓扑优化设计方法研究

焊点布置的设计对于车身结构的强度、刚度、NVH特性和耐撞性等都有重要影响。针对一种紧凑型两厢轿车,分别以车身结构的刚度和低频固有振动特性为设计目标,对车身结构中的焊点布置进行了优化设计。通过对优化设计结果的理论分析和工程评价,对相关的优化设计问题定义的有效性和优化设计方法的适用性进行了分析。基于相关分析结论和车身结构设计经验,提出了一种新的车身结构焊点布置的分区拓扑优化设计方法,通过将车身划分为多个功能设计区域,可以采用分级优化设计的方法综合考虑车身结构的刚度和动态特性、耐撞性以及强度等多方面的性能要求。通过对一个实际轿车车身结构中焊点布置的重新优化设计,验证了提出的优化设计方法的有效性,同时表明该车身的现有焊点布置方案已接近最优设计。

Multi-domain synthetic topology optimization method for automotive body spot weld layout design

Spot weld layout (SWL) design has great influence on the strength, stiffness, NVH and crashworthiness characteristics of automotive bodies. Optimizations of the SWL of a compact hatch back car body are performed with the objective of maximizing its torsion stiffness and lower order modal frequencies respectively. Analysis of the optimization results from both theoretical and engineering points of view is performed to evaluate effectiveness of the optimization problem formulations and the optimization methods as well. Based on the analysis results and related automotive body structural design theory and experiences, a multi-domain synthetic topology optimization method is developed for optimal automotive body SWL design. With this method, an automotive body is partitioned into several different functional domains, based on which a multilevel optimization process is employed to conduct synthetic optimization of the strength, stiffness, NVH and crashworthiness of the automotive body. Optimization of the SWL of a practical car body validates the proposed design optimization method and also indicates that its present SWL design is nearly optimal.