关键词: 车身设计;截面形状;离散优化;遗传算法

Abstract: Through the study of the automotive body beam cross-section optimization, the method couples the continuous optimization problem, such as cross-section shape, with the discrete variable optimization problems, such as types of section material and their thickness. With the assembly and manufacturability in the engineering design as design constraints, an automotive body thin-walled beam cross-section multi-objective optimization method is established. The method build a multi-objective optimization model with the vehicle body beam structure performance, cost, weight as design goals, the section shape, thickness, material as design variables by using a special coding way for the section shape. NSGA-II genetic algorithm is applied to solve the multi-objective optimization, and a material parameters and standard thickness database is built in the method. The case proves that this method not only can be used to quickly obtain the beam cross-sectional shape and material parameters, which meets the design goals and the requirements of engineering design in the conceptual design phase, but also can work in detailed engineering phase to optimize the local shape for the beam to improve the body stiffness while decreasing the body mass.

Key words: vehicle body design;section shape;discrete optimization;genetic algorithm