Research On The Influence Of Rubber Bushing On The Performance Of The Crossover's Independent Rear Suspension

Suspension system,as the important part of the chassis system,is the key component of attenuating roads' excitation.In the course of vehicle driving,the suspension's performance directly affects the vehicle's handling stability,ride comfort and NVH(Noise,Vibration&Hashness).Suspension's rubber bushings as the connecting element of the suspension system is the essential part of the suspension system,whose main function is to restrain the relative motion between the suspension components,to buffer the vibration,and to make up the assembly manufacturing error.The design and matching of the rubber bushings is very important about the performance of suspension to improve the vehicle's performents.In this paper,the crossover vehicle's independent suspension as the research object,the change of rubber bushings' mechanical properties was analysed,whose influence on the suspension stability and comfort was deeply studied.On the basis of these effects,the mechanical properties of rubber bushing were optimized.The main research contents are as follows:Firstly,in view of the traditional suspension dynamics analysis,it was difficult to accurately reflect the influence of the rubber bushings about the suspension because of the linear elastic model of bushings.Based on the analysis of Kelvin-Voigt model,three parameters of Maxwell model,BERG model and DZIERZEK model,a high precision mathematical model,which include super elastic unit,the fractional derivative viscoelastic element and smooth friction unit stack,was established.The model parameters was identified through the static and dynamic test and finite element simulation data the rubber bushing.The results of the theoretical model and the experimental results were analyzed and compared.The accuracy of the rubber bushings' theoretical model was verified.Secondly,based on the precise mechanical properties of rubber bushings,the suspension kinematics model consists of rubber bushing force characteristics was established based on the knowledge of advanced mechanism kinematics.The K&C characteristic parameters of the suspension were calculated,and the results were compared with the results of the rigid suspension system model.the study shows that the mechanical properties of the rubber bushings have a certain effect on the suspension's K&C property.By changing the stiffness of rubber bushing,this effect was further analyzed.The independent rear suspension virtual prototype was built byADAMS,the correctness of dynamic simulation verified the theoretical model and the theoretical analysis.What's more,the vehicle virtual prototype of ADAMS was built.the effect of rubber bushing on the ride comfort was studied.The results show that the rubber bushing can absorb part of the vibration energy,which verifies the effect of the rubber bushing on the ride comfort of the suspension.Finally,the influence of the each stiffness of the rubber bushing about the handling stability(K&C characteristics)and the ride comfort of the suspension is studied based on the rubber bushing stiffness' sensitivity.Based on the sensitivity analysis,the rubber bushings' stiffness was optimized.The research results of this paper have an important role in improving the performance of suspension,and provide guidance for the matching and optimization design of suspensions' rubber bushings.