차체 무게 저감을 위한 정강성 성능의 민감도 기반 최적설계에 관한 연구

Fuel economy, Driving performance, Material cost and environment effects could be improved by reducing vehicle body mass. On the other hand, performances affected by vehicle body stiffness such as Handling performance, Durability and NVH could be degraded because of mass reduction. For this reason, MDO(Multi Disciplinary Optimization) method could be considered to satisfy all conflicted performances. Gradient based optimization is a numerical method using performance’s gradient information. In this study, the Adjoint variable method was applied to calculate performance’s gradient because the number of design variables is much more than the number of constraints. And MFD(Method of Feasible Directions) optimal searching algorithm was applied to satisfy a lot of performance targets. The main purpose of this study is to find an optimal design with minimized mass meeting constraint conditions such as Torsional stiffness and Suspension mount position’s local stiffness.