A Study of Front Subframe System Optimization for Improving Vehicle NVH Performance

The purpose of this article is to investigate the links between NVH performances of a car such as booming, road noise and dynamic characteristics of its front subframe system. The target of dynamic property of the subframe members was set through a contribution analysis. The Booming noise was refined by improving the structural dynamic stiffness of relevant subframe members and optimizing the dynamic stiffness of subframe mount bushes considering the frequency property of the engine exciting force. In the light of NVH, merits and demerits of a solid mounted subframe for various powertrain types were examined, and several countermeasures such as structural reinforcement, dynamic dampers and dynamic characteristics of A and G bushes were applied and suggested.