Bus Skeleton Lightweight Design Based on Reduced Model and Mixed Variables Optimization
A new method integrating reduced model and mixed design variables is proposed and applied in the lightweight design of a bus skeleton for the purpose of mass reduction without loss in structural performance. A whole skeleton model and a reduced model are built. All parts except chassis and floor assembly are reduced out using static reduction method. Reduced model is verified with finite element analysis (FEA) results compared with those from whole model. The study shows that a close agreement of computed results of whole and reduced models is obtained in terms of deformation and displacements at load-bearing nodes and normal mode shapes. While slight discrepancy in first mode frequencies is observed because the static condensation method for reduced model is approximate for mass matrix. As a result, the reduced model saves computation time by about 50 per cent compared to whole model. A structural size optimization is carried out for bus skeleton lightweight issue. Considering size specifications of structure members, three computer-aided engineering (CAE) models with fully discrete design variables, mixed design variables (combination of continuous and discrete variables) and fully continuous variables are built and solved respectively. A comprehensive comparison is examined on the basis of optimized results such as mass reduction, structural performance and computation cost. The results show that adopting the optimization model (scheme) with the reduced model and the mixed design variables, a compromise with 4 per cent mass-saving is obtained between lightweight objective and computing cost. Moreover, optimized results totally accord with size specifications of bus skeleton, which means no manual adjustment is required and makes the proposed method feasible for engineering application.
lightweight reduced model mixed variables optimization bus skeleton
Yi Li Fengchong Lan Jiqing Chen Jianqiang Rao
School of Mechnical & Automotive Engineering South China University of Technology Guangzhou China School of Mechanical & Automotive Engineering South China University of Technology Guangzhou China
国际会议
成都
英文
585-589
2010-07-07（万方平台首次上网日期，不代表论文的发表时间）