Wishbone Lightweight Design Of A Medium-sized Sport Utility Vehicle

In the SUV suspension system, in order to reduce unsprung mass and enhance the carrying capacity of suspension, Arm's structural stiffness and strength not only need to meet the requirements of the premise, but also need to optimize the structure of the weight as much as possible. However, because of the complicated boundary of arm, it is blind to only use lightweight materials to lightweight the mass, and it is also limited to use the structural optimization techniques to optimize the structure. so, this paper proposes two sets of lightweight design programs by combining with the suspension of a mid-sized SUV projects. Before the plan, we first analyze the cast steel material arm by finite element method. In the first program, the forged aluminum alloy materials is used to redesign arm's structure in structural topology optimization, then reanalyze the new designed aluminum arm. Optimization result shows that the aluminum alloy swing arm meets the conditions under strength and stiffness required in the circumstances, and the weight is reduced about 12.23% with respect to the steel one. In the second program, carbon fiber composite materials is used to redesign the structure, and we propose a two-stage design method, The first stage of the program uses first program's topology optimization method to redesign the carbon fiber composite material structure; and analyze the new designed composite arm by the finite element method, analysis shows that there are surplus in the strength, so we need to optimaze the structure further. In the second stage, the arm is optimized to obtain the optimal thickness of overlay by size optimization, the analysis of the second phase of the optimized composite material swing arm shows that the new arm is weakened, but meet the design requirements. The second design of composite materials swing arm to meet the conditions under arm strength and stiffness required in the circumstances, the weight of the arm is reduced about 66.25% with respect to the steel material. comparison of the two sets of structural design of the arm strength, stiffness, mass, natural frequency performance, the second program of composite materials structure get a better weight loss and achieve a more pronounced effect.