摘要
车身结构轻量化设计需要满足模态、刚度和碰撞安全等多项性能要求;同时为了提高设计方案的鲁棒性,必须在设计过程中考虑不确定性因素的影响。在各种方法中,非支配排序遗传算法NSGA-Ⅱ在工程设计的多目标和可靠性设计中应用越来越广泛。在采用高强度钢板后,为确定某车身前端结构的关键零件的厚度参数,分别建立白车身有限元模型和40%偏置正面碰撞的简化模型;在优化模型中综合考虑白车身扭转刚度、最大碰撞力及平均作用力、碰撞吸能要求和质量最轻等多个性能指标要求,在构建高精度的响应面近似模型的基础上,采用非支配排序遗传算法(NSGA-Ⅱ)对其进行6σ可靠性优化设计;运用蒙特卡罗模拟技术对优化方案的鲁棒性进行评价。优化结果提高了整车的碰撞安全性,同时白车身扭转刚度和零件重量得到了很好的控制。
Lightweight design of car body structure is in demand to meet performance requirements of modes,stiffness,collision safety,etc.In order to improve the robustness of design,the uncertainty factors in the design process must be considered.In a variety of optimization designs,non-dominated sorting genetic algorithm NSGA-Ⅱis more and more widely used in the multi-objective and reliability engineering design.After application of high strength steel to the body structure in attempt for lightweight,the investigative procedures are carried out as follows to determine the effective thickness values of the key structure components in the front body structure： first,the finite element models of both the body in white and the 40% offset frontal collision are established;second,the property indexes including the torsional stiffness of entire body in white,the maximum collision force and the mean acting force,the collision energy absorption and the minimum mass etc.are considered throughout in the multi-optimization model,and then the NSGA-Ⅱ algorithm is used to perform 6σ reliability optimization based on the high-precision response surface approximation model;at last,Monte Carlo simulation technique is used to evaluate the robustness performance of the optimization scheme.The optimization results show that the vehicle collision safety performance is improved and the body torsional stiffness and structural component weight are well controlled.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2011年第4期117-124,共8页
Journal of Mechanical Engineering
基金
科技部国际科技合作(2008DFB50020)
中央高校基本科研业务费专项资金(2009220002)资助项目
关键词
车身结构
轻量化
多目标优化
可靠性设计
Carbody structure Lightweight Multi-objective optimization Reliability design
