基于二次优化法的铝合金车架可靠优化设计研究  

Reliability design of aluminum alloy frame based on quadratic optimization method

作　　者：李皓 王震虎[1,2] 李落星 朱学武[3] LI Hao;WANG Zhen-hu;LI Luo-xing;ZHU Xue-wu(State Key Laboratory of Advanced Design and Manufacture for Vehicle Body,Hunan University,Changsha 410082,China;College of Mechanical and Vehicle Engineering,Hunan University,Changsha 410082,China;State key Laboratory of Comprehensive Technology on Automobile Vibration and Noise&Safety Control,China FAW Group Co.,Ltd.,General Research Institute,Changchun 130011,China)

机构地区：[1]湖南大学汽车车身先进设计制造国家重点实验室,湖南长沙410082 [2]湖南大学机械与运载工程学院,湖南长沙410082 [3]中国第一汽车集团有限公司研发总院汽车振动噪声与安全控制综合技术国家重点实验室,吉林长春130011

出　　处：《机电工程》2019年第11期1119-1125,共7页Journal of Mechanical & Electrical Engineering

基　　金：国家重点研发计划项目(2016YFB0101700);国家自然科学基金重点资助项目(U1664252,51605234);汽车振动噪声与安全控制综合技术国家重点实验室开发基金资助项目(1803J)

摘　　要：针对基于可靠性的多目标优化过程中,解收敛过早且计算效率低下的问题,提出了基于可靠性的二次优化法。根据Pareto前沿解单位法向量来计算多个优化目标的权系数,使用序列二次规划法对多目标优化结果进行了二次优化,并通过矩方法进行了可靠性分析;以某铝合金新能源汽车车架为例,结合试验设计、近似建模、二次优化法和矩方法,以零件壁厚为设计变量,一阶弯扭模态频率和弯曲刚度为约束,铝合金车架质量和扭转刚度作为优化目标,进行了多目标可靠性优化设计。研究结果表明:二次优化法使最优解落在约束边界,解决了基于可靠性的多目标收敛过早的问题;矩方法在保证可靠性优化精度的同时提高了优化效率;与原设计相比,优化后的铝合金车架扭转刚度提高12.96%,车架总质量减小5.41 kg。Aiming at the problem of premature convergence and low efficiency of calculation in reliability-based multi-objective optimization,a reliability-based quadratic optimization method was proposed.According to the unit normal vector of Pareto frontier solution,the weight coefficients of multiple optimization objectives were calculated.Sequential quadratic programming was used to quadratically optimize the results of multi-objective optimization,and reliability analysis was carried out by moment based method.Combined with experimental design,approximate modeling,quadratic optimization algorithm and moment based method,multi-objective reliability based optimization design was carried out for an aluminium alloy new energy vehicle frame with the wall thickness of parts as design variables,the first-order mode frequency of bending and torsion and the bending stiffness as constraints,the quality and the torsion stiffness of aluminium alloy frame as optimization objectives.The results indicate that the optimal solution is located on the constraint boundary and the problem of premature multi-objective convergence based on reliability is solved.The moment based method improves the optimization efficiency while guaranteeing the accuracy of reliability optimization.Compared with the original design,the torsional stiffness is increased by 12.96%,and the total mass is decreased by 5.41 kg.

关 键 词：铝合金车架 矩方法 多目标优化 二次优化法 

分 类 号：TH122[机械工程—机械设计及理论] U462.35[机械工程—车辆工程]