Structure Design And Analysis Of Pure Electric City Bus Body Based On Topology Optimization

The body structure of pure electric city bus have changed due to a changing that the E-motor take the place of engine. Bringing topology optimization in conceptual design of the new type of bus body play an important rule in the bus body design.In resent years,more and more scholars focus on topology research with the high speed development of topology. The application of topology have brought great economic benefits in many fields such as car aerospace architecture and so on. In this paper,the author summarized topology optimization firstly; Secondly,discussed the situation of the research in the field of topology optimization and the significance of using topology optimization method in the automobile structure design; Lastly, selected topology optimization method to optimize and design the bus body structure.Then, introduced the basic theory of optimization method and topology optimization method, discussed the characteristic and application method of the homogenization method variable thickness method independent continuous mapping method;studied mathematics algorithm of the topology optimization,such as sequence linear programming sequential quadratic programming sequential augmented Lagrangian method and so on;Selected the variable density method which is based on simp interpolation method as the topology optimization method to optimize the pure electric city bus body.Lastly, optimized the body of pure electric city bus based on multi-objective topology optimization on multi-condition. Introduced the basic multi-objective topology optimization. The mathematic mode was established according to the compliance of four typical conditions and the first six orders of normal mode of the bus body. The finite element mode was established according to the concept design demand of the pure electric city bus. Iterative calculation of the bus body mode was conducted with the help of Optistruct software. It is conclude that the topology optimization analysis is reliable through the analysis of iterative curve. The bus body structure was established based on the result of topology optimization.The finite element analysis of the pure electric city bus was conducted. the main content of analysis were the static strength and stiffness of the bus body consider its four typical condition and the first six orders of normal mode of the bus body. The finite element analysis result show that the strength and stiffness of the bus body meets requirements, and the low orders of normal mode of the bus body has stay away from the sensitive frequency range.