Lightweight Design And Fatigue Life Prediction Analysis For Rear Anti-roll Stabilizer Of The Passenger Vehicle

Vehicle lightweight is one of the effective measures to realize the green vehicle industry.In the process of modern vehicle structure design,lightweight has been paid more and more attention.The lightweight design of vehicle anti-roll stabilizer and the fatigue life analysis after lightweight design are important parts of the design and development of vehicle suspension components.This project originates from the school-enterprise cooperation project.According to the enterprise requirements,the research team designed and developed a passenger vehicle anti-roll stabilizer.The main task is to lighten the weight of the anti-roll bar and the connecting rod,which greatly reduces the quality of the original anti-roll stabilizer.At the same time,the simulation analysis of the handling stability dynamics and fatigue life of a passenger vehicle after the lightweight design has been completed,which verifies the feasibility of lightweight design scheme for rear anti-roll stabilizer of a passenger vehicle.Firstly,the structure,working principle,equivalent inclination stiffness and strength checking calculation method of anti-roll bar are analyzed,and the dynamic analysis of anti-roll bar is carried out from two aspects of roll vibration and handling stability.On this basis,the primary design scheme of anti-roll bar structure is put forward,and the lightweight design of anti-roll bar structure is carried out according to the hollow theory,and the Finite element analysis model of anti-roll bar before and after lightening is established.The strength analysis,load analysis and modal analysis of anti-roll bar before and after lightening are completed.The structure effectiveness of lightweight design for anti-roll bar is verified.Secondly,according to the design requirements of the enterprise,the structural design scheme of the connecting rod is put forward,and the structural optimization design of the connecting rod's rod,ball pin end and seal is completed.Lightweight materials are selected according to the technical requirements and the structural optimization scheme of the connecting rod,of which PA66+GF45% and high temperature nylon PPA are optimally selected.And the structural performance of lightweight connecting rod are Compared and analyzed from the aspects of working loads,pin pull-out force,pin pressure pull-out force and tensile strength according to the performance of the two materials,finally the lightweight design scheme of connecting rod structure and the selection scheme of lightweight material(i.e.high temperature nylon PPA)were determined.Thirdly,on the basis of the finite element analysis in Chapter 2 and Chapter 3,the flexibility of the anti-roll stabilizer is processed by use of the modal analysis file,so that the rigid-flexible coupling model of the anti-roll stabilizer is established in ADAMS/Car,then the rigid-flexible coupling dynamic model of the vehicle with the anti-roll stabilizer is established by using the ADAMS/Car module.The working load of the connecting point of the anti-roll bar and the connecting rod is extracted and compared with the actual load table provided by the enterprise to validate the accuracy of the model,and the simulation analysis of cornering events and step steer are completed according to the vehicle handling stability test evaluation method,which verify the feasibility of the anti-roll stabilizer lightweight design scheme.Finally,the fatigue simulation analysis of the lightweight anti-roll bar and connecting rod are carried out in the nCode software.The fatigue life simulation analysis processes of the anti-roll bar and the connecting rod are established and their fatigue life are obtained by use of nominal stress method respectively.The results show that the lightweight design scheme of the anti-roll stabilizer is feasible.