Fatigue Analysis Of A Passenger Car Subframe

The emergence of the car’s subframe with its powerful advantage is rapidly becoming a mainstream automotive chassis parts, which not only improve the performance of the vehicle suspension system also makes assembly more convenient, design tends to be more universal.Because of the vehicle’s complex and changing road conditions,subframe as a key component of the vehicle’s chassis, the environment in which the load is also very complex, it is more prone to damage.Therefore, the safety and reliability are important factors must be considered at subframe design and development process.In this paper,the research for the fatigue analysis of a certain type of passenger car’s subframe was carried out.Provide technical reference for the subframe and other components in the design and development phase of the vehicle.In this paper, combined with multi-body dynamics theory, finite element theory and fatigue life analysis theory,the simulation analysis was carried out to obtain stress, deformation,and the fatigue life distribution information by using CAE Technology.And then to verify the results accuracy of the analysis by the subframe fatigue bench test.Firstly,established finite element analysis model of the passenger car’s subframe by using Hypermesh.Multi-body dynamics simulation was carried out in 12 static conditions by using ADAMS,then got the load of each hard point(mount point) on subframe in order to provide the input load of structural strength analysis.Based on the principle of inertia relief and using HyperWorks / RADIOSS solver for subframe’s structural strength of 12 static conditions were calculated, the stress concentration of subframe was obtained and then checked the results of strength analysis.Based on the results of finite element static analysis and using nSoft software to calculate the fatigue life of the subframe.Got the fatigue life distribution of subframe and analyzed, and then through the subframe fatigue bench test to verify the analysis results.This article uses the finite element analysis method with a combination of multi-body dynamics for the subframe’s structural strength and fatigue life analysis.Verify that the subframe’s structure meet the design requirements.It has a certain guiding significance for the new products of auto enterprise in design and improvement phase.