Multi-objective size optimization design for bus body frame structure based on relative sensitivity analysis

摘要

In this paper, on the premise of not affecting the optimization results, the number of variables of the bus body frame structure was effectively reduced by applying design variable batch processing. The relative sensitivity of four structural strain energy responses were first obtained. These are, namely, the first order bending and torsion modal frequencies, and the bending and torsion stiffness with respect to the mass. These values were then used to select the design variables for multi-objective size optimization design. The selected variables are sensitive to decreases in weight but insensitive to the body frame structure's performance. Finally, the optimal size parameters of all components and the body frame structure's lightweight design scheme after rounding were obtained. The optimization results indicate that the mass of the optimized body frame is significantly reduced, by 303kg, with an 11.07% weight reduction, whilst keeping its performance basically unchanged.