Fatigue Simulation Analysis And Structural Improvement For Torsion Beam Suspension

With the continuous development of automotive industry,automotive manufacturers and consumers pay more and more attention to automobile safety.The fatigue life of vehicle part is a evaluating indicator of full vehicle performance.In the past,the fatigue life of vehicle part is mainly to be test by vehicle road test on the proving ground,which not only consumes a great deal of manpower and material resources,but also increases the time of vehicle development.With the rapid development of computer technology,finite element analysis of fatigue technology is a fatigue analysis method based on finite element theory.This method effectively uses virtual test field to analyze the fatigue life,whi ch ca n greatly save the cost of the whole vehicle fatigue test and shorten the cycle of vehicle development.Suspension performance effects vehicle performance,it is an important part of the vehicle structure.The twist beam suspension is a half independe nt suspension,because of its simple structure,low cost and convenient maintenance,it is used in the front engine front drive vehicles as a rear suspension.The rear suspension which article researches will result in fatigue damage because of the impact of road surface,low fatigue life will effect brand images and the safety of drivers and passengers.So it is important to improve the fatigue life of twist beam suspension,fatigue life analysis method based on finite element theory is convenient to achieve that purpose.In this paper,the research object is the rear suspension of the same accident vehicle.First,using 3D scanner scans the rear suspension to get the cloud.Secondly,using CATIA reverse engineering to establish the three-dimensional model of the rear suspension.Then,establishing the finite element model and checking the static strength under the four extreme working conditions by Optistruct solver.At the same time,using Nastran solver to analyze the free mode and get the frequencies,shapes and flexible neutral file.Then,importing the rear suspension flexible file to ADAMS,combining that with the mcpherson front suspension system,steering system,tire system and body system to establish the vehicle dynamic model.Using integrated durability pavement spectrum to carry on the analysis and getting the displacement of each mode of the rear suspension.Finally,according to the modal displacement and material's S-N curve,we can do the fatigue life analysis and get the fatigue life nephogram.At the same time,according to the result,we can optimize the structure of the twist beam rear suspension and improve the fatigue life.