Conceptual design of the front-end structure of automobile considering crashworthiness: a three-stage target decomposition method

摘要

The front-end structure crashworthiness design during the conceptual design phase of automobile can shorten production cycle and has a great significance to improve safety. This paper proposes a three-stage target decomposition method to design crash pulse and manage the crash energy absorption of front-end structure of automobile. In this method, the theoretical optimal solution of the Equivalent Dual-trapezia Wave (EDTW) is calculated by the overall layout parameters of automobile and safety requirements of occupant. The optimal EDTW, as the target crash pulse, is decomposed to segments based on the reserved longitudinal crush space and the lateral energy absorption ratio of the front-end substructure. In addition, simple mathematical and mechanical principles are applied to calculate the performance objectives of key energy absorption substructures. Finally, an empirical application of M6 model is conduct to verify the validity of EDTW optimal solution and the realizability of target decomposition. The result shows that this proposed method is effective for the conceptual design of new cars and model change of existing cars. The design process does not rely on large computing software and empirical data and the design result has a guiding role in CAE analysis of automobile safety.