Abstract: A multidisciplinary design optimization (MDO), considering lightweight, stiffness, strength, vibration mode and rollover, is implemented to an integral bus body structure to improve its synthetic performance. To conquer the difficulty of high nonlinearity brought by rollover analysis and to resolve the time consuming problem of structural finite element (FE) analysis, multidisciplinary approximate models are built. The FE models of the bus body are established, in which the stiffness, strength and vibration mode analyses are finished by Msc.Nastran, and the rollover analysis is solved by the explicit dynamic software Ls-dyna. The disciplinary variables are selected on the basis of technological requirements and sensitivity analysis results. The experimental design is finished by using optimal Latin hypercube method. Then the multidisciplinary approximate models are constructed by using the response surface method. The MDO problem is solved by using collaborative optimization approach. The result shows that the optimal solution is better than the original design in aspects of lightweight, stiffness, strength, modal vibration, and safety of rollover.

Key words: Bus body, Collaborative optimization, Multidisciplinary design, Response surface method