서브프레임 등가모델을 이용한 전차량 모델의 진동특성 분석 방법

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 technique is 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 to construct the analysis model. 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. The component mode synthesis (CMS) method is adopted to reduce the number of degrees of freedom of structures composed of two or more substructures, without losing the mean physical characteristics of the structure. 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. Vibration characteristics, such as modal results and frequency response, of the vehicle system are obtained. The effects of some design parameters variations on the vibration characteristics of full vehicle model are also investigated.