Multi-objective topology optimization for electric car body based on SIMP theory

For obtaining a rational load bearing structure of electric car body in conceptual design phase, a multi-objective topology optimization is performed with consideration of both static and dynamic characteristics. Based on solid isotropic material with punishment (SIMP) theory, the objective functions for multi-static-conditions and dynamic vibration frequency are defined by compromise programming and average frequency methods respectively and are normalized to eliminate the discrepancy in the order of magnitude. The optimality criteria method is used to update design variables, and a topological structure of electric car body meeting both requirements of static stiffness and dynamic vibration frequency is finally obtained by optimization iteration.