Lightweight Design and Multi-objective Optimization for a Lower Control Arm Considering Multi-Disciplinary Constraint Condition 2019-01-0822
Requirement for low emissions and better vehicle performance has led to the demand for lightweight vehicle structures. Two new lightweight methods of design and optimization of the lower control arm were proposed in this research to improve the efficiency of the traditional lightweight method. Prior to the two lightweight optimization and design methods, the static performance, including stiffness,strength and mode, and fatigue performance of the lower control arm were analyzed and constraints were provided for subsequent optimization and design. The first method of lightweight design and optimization was integrate application of topography optimization, size optimization, shape optimization and free shape optimization for the control arm. Topography optimization was first applied to find the optimal reinforcement rib distribution form of the lower control arm. Size optimization was then applied in this study to optimize the plate thickness. Shape optimization was applied to determine the optimal radius of the control arm arc. This would ensure the stiffness of the control arm. Free shape optimization was also applied in this step to determine the best flanging length. This method reduced weight by 32.3%.The second approach of lightweight design and optimization was multi-objective optimization for the lower control arm. The material of the lower control arm replaced steels with lighter aluminum alloy. Topology optimization was also applied in this step to obtain a better distribution of the aluminum alloy. Multi-objective optimization of control arms was applied through parametric modeling and using Latin hypercube sampling method. This method reduced weight by 52%. The results indicated that the lightweight was achieved successfully while keeping the main performance uncompromised. This two methods of design and optimization of the lower control arm provides guidance for other vehicle parts lightweight development and has potential applications in field of automotive industry.