Analysis of vibration characteristics of full vehicle model using substructure synthesis method

Abstract

The large structure, such as passenger vehicle or aircraft, cannot be modeled into simple vibration system because the various substructures were complicatedly combined each other. So, the finite element method is a generally used to model and simulate the physical behavior of bodies with arbitrary shape. However, FE analysis requires a huge amount of computation time and cost. Accordingly, the vibration characteristics of large structural systems are often analyzed using the component mode synthesis techniques which is one of the substructure synthesis methods. In this study, an analysis of vibration characteristics of passenger vehicle applying substructure synthesis method is performed. The passenger vehicle model, consisting of a vehicle body, suspension systems and sub-frame, is presented. The physical parts of the vehicle system are idealized as equivalent substructures using the Craig-Bampton method of CMS. Applying the modal synthesis technique, a formulation is obtained for the substructures of the vehicle system. Vibration characteristics, such as modal results and frequency response, of the vehicle system are obtained by solving the formulation. The effects of some design parameters of sub-frame on the vibration characteristics of full vehicle model are also investigated.