Research On The Influence Of Nonlinear Damping And The Optimization Of Auto Parts Of Rear Suspension

Suspension is one of the most important parts of the automobile chassis.The comfort and stability of the vehicle is affected by the performance of the suspension.In order to improve the performance of the vehicle,the dependent suspension is updated to independent suspension by some vehicle company.Based on the previous research,further study is made on the independent suspension of the Crossover.Firstly,the dynamic model with twelve degrees of freedom and the corresponding equation are established based on the Crossover.The analysis is made to study how the nonlinear characteristic of the damper of rear suspension affect the performance of the vehicle through MATLAB/Simulink.Compared with the linear suspension,nonlinear suspension has certain influence on the displacement and the acceleration of the mass of the body and the acceleration of the mass of the chair system and the dynamic displacement of the suspension.The degree of influence varies with the grade of pavement and the speed of vehicle.The study shows it is necessary to consider the nonlinear characteristic of the damper when making research on suspension.Secondly,to get more accurate results,the upper arm,lower arm and the stabilizer bar of the suspension are considered as flexible body.The rigid flexible coupling and nonlinear model of suspension and vehicle are established based on ADAMS/Car and ANSYS.Compared with the rigid model,the toe angle,camber angle and tire lateral displacement of the rigid flexible coupling and nonlinear model are different when making reverse rotation simulation and the vibration of the body of the vehicle is lower when doing ride comfort simulation.The study shows it is necessary to consider the flexible body of the suspension when making research on suspension.Thirdly,static simulation is done to get the load of the surface of the bushing when the crossover working in maximum vertical force condition,maximum lateral force condition and braking condition.Based on the load,static analysis is made on the upper arm,lower arm and H shape control arm by ANSYS-Workbench.The results show that arms of suspension meet the strength requirement and there is some space to lightweight the arm.Muti-objective optimization is made on upper arm andlower arm.Shape-optimization is made on H shape control arm.After optimization,the weight loss of the three arms is 11.6%,11.4%,5.15%.Finally,in order to study the reliability of the new model,fatigue Tool of ANSYS-Workbench is used to do fatigue simulation.The results show the fatigue life and the safety factor of suspension meet the requirements under three different working conditions.The fatigue simulation shows the reliability of the optimization.