Dynamic Damper를 갖는 차량 서브프레임 FOA 모델의 진동 특성 연구

A sub-frame is a structural component of a vehicle to sustain the engine and the drive train. The principal purpose of using a sub-frame is to isolate the vibration and the harshness coming from the engine and the road. So, it is important to investigate the vibration characteristics of a sub-frame in the initial design. A dynamic damper can be used to control the vibration characteristics of a sub-frame. It is shown that a dynamic damper can reduce the magnitude of the frequency response function of a sub-frame and effectively suppress the force generated by the engine and transmission. In this study, the FOA (First Order Analysis) modeling technique is employed to design a vehicle sub-frame instead of using a full scale finite element model. A dynamic damper is mounted on the sub-frame FOA model which only consists of beam elements. The mass, stiffness and damping ratio effects of the dynamic damper on the vibration characteristics are investigated.