Analysis On Structural Optimization Design And Accelerated Fatigue Of Vehicle Rear Subframe

With the emphasis on environmental protection,as well as the development of automotive technology,lightweight design of the vehicle has become a hot research topic.Structural optimization,as an important lightweight method,has been widely used.The rear subframe is used as an important chassis part,reduce the weight of the structure is of great significance to enhance the vehicle performance and reduce costs.The fatigue failure analysis is also necessary because the failure of the rear su-bframe is mainly fatigue failure.Based on the company's rear subframe improvement project,briefly introduces the background and significance of the research of sub frame,And the research status of structural optimization and accelerated fatigue analysis is expounded,then this work proposed the research contents and routes.According to the requirements of the improvement project,Firstly,the static and dynamic performance of the rear subframe is analyzed,including strength analysis,rigidity analysis of each installation point,free modal analysis.Thus obtain the main performance indicators that meet the requirements,Then taking these index value as the objective and constraint,the conceptual optimization design and detailed optimization design of the rear subframe are carried out,At last the new rear subframe structure which meet performance rerequirements and less weight is designed.As the bench test cycle is longer,in order to shorten the fatigue test time,Then the accelerating method fatigue which combine relative damage spectrum analysis with fatigue data editing is described.The purpose of fatigue acceleration is achieved by reducing the total number of cycle cycles while reducing the load time of each load spectrum,And analyze the load characteristics of the original spectrum and the acceleration spectrum.Finally,the CAE fatigue analysis technique is carried out to analyze the fatigue lives of the pre-optimized and optimized rear subframe.The research results show that the rear subframe obtained through the optimization process meets the basic required performances,and remarkably lighter than the original one.The proposed process of structure lightweight optimization and fatigue performance analysis of the rear subframe can be used as a reference for design projects of other chassis components.