Multilevel optimisation method for vehicle body in conceptual design

Since product development lead-time needs to be as short as possible in contemporary enterprises, it is necessary to assess and optimise the performance of the structure in conceptual design phase for avoiding the time consuming production of trial models for vehicle body. This paper proposes a conceptual design tool based on optimisation algorithms for global body frames named vehicle concept design-intelligent CAE system (VCD-ICAE). A multilevel optimisation algorithm is applied to optimise the body performance, to decide the size parameters and generate cross-sectional shapes that satisfy design engineers' required characteristics. The global body stiffness and vibration property would be optimised while decreasing the mass of body. The paper describes the implementation of the optimal algorithm, and genetic algorithms are applied to solve the optimisation problem. A case of optimisation for a real car is given to verify the validity of the algorithm.