Lightweight Design Of Composite Automotive Suspension Control ARM Structure

The lightweight design of suspension control arm is an important research content of the automobile chassis.Composite material with its excellent material properties,its application to the lightweight design of control arm has great research significance.In this paper,the geometrical structure design of composite control arm,the optimization design of lay up and the design of the bonded-bolted hybrid joints are carried out respectively,which provides a reference for the development of composite structure optimization design theory and method.Firstly,taking the steel suspension control arm as reference,the load of several kinds of driving conditions which was analyzed by using the multi-body dynamics was considered as the boundary condition for the finite element analysis,then the stiffness,strength and natural frequency were analyzed,which was used as a reference for the following.Secondly,the design requirements of composite structure in the forming process,structure with openings and joint structure were studied,then based on the structural characteristics of the control arm main body and the joints,the geometrical structure design of composite control arm was completed on the basis of the steel control arm.And the composite-steel mixed structure design for joints was determined.Thirdly,Based on the lay up design features,the structure optimization design methods and processes considering the sequence relationships of laminate thickness,stacking angles and lay up design requirements in the design process were put forward.The first step,the laminate thickness was designed using the quasi-isotropic plies.And the composite structure could meet the basic performance requirements.The second step,the optimization of stacking angles was carried out using genetic algorithm to improve the structure performance.The third step,based on the principle of lay up design,the Pareto solution set was filtered to complete the lay up design.finally,the effectiveness of the proposed method and the effect of lightweight were verified.Finally,based on the study of the load of the bolted connection portion and bonded connection portion in the bonded-bolted hybrid composite joints,the finite element model of the bonded-bolted hybrid joints was established,and compared existing research results to validate the model.According to the main influencing factors of the carrying capacity of the joints,combined with the structural characteristics of composite control arm,the design,analysis and verification of its joints were completed.The results show that the final composite control arm structure has better structural performance,the joints meets the design requirements,and weight reduced by 29.23%,lightweight effect is obvious.