离散变量三段式车架轻量化设计

Base on Discrete Variable Three-Stage of Frame Light Weight Design

研究优化设计中设计变量的离散化处理,完成三段式车架的静动态特性分析和轻量化设计。首先,以某中型越野车车架为优化对象,采用实验设计方法进行了设计变量的灵敏度分析,并在对设计变量进行必要的取舍基础上建立了结构优化模型。其次,采用多岛遗传优化算法计算车架在三种工况下的最大应力、位移和自由模态下的固有频率,以完成在结构满足固有频率、几何尺寸和强度等约束条件下的车架各板材离散化尺寸的优化。优化结果表明:在可行域范围内,不仅使车架的质量降低了5.7%还避开了激励频率。

Research design variable discrete processing in design optimization,complete the static and dynamic analysis and light weight design of three-stage of frame. Firstly,take a medium-sized SUV frame as the object of study,analyze the sensitivity of design variables with the method of design of experiment,and build the structure optimization model with some necessary trade-offs of design variables. Then,compute the maximum stress and displacement in three work conditions and the natural frequency in free mode in using multi-island genetic algorithm,to optimize the discrete dimension of frame sheet on the premise of the frame could satisfy the conditions of natural frequency,geometry and strength. The optimization results show：In the range of feasible region,not only reducing the frame weight of 5.7% but also keeping off the excitation frequency.