Research On Optimization Of Suspension Bushing For Key Performance Of Vehicles

The advantages of car handling stability and ride comfort performance not only determine the convenience of car operation and the safety of high-speed driving,but also determine the comfort of vibration environment where passengers are located,which has a great impact on the fatigue life of components,and it is the focus of modern vehicle design.Suspension rubber bushings are widely used in the connection between suspension and body.Due to their superelasticity and viscoelastic properties,they have a good vibration and noise reduction effect,which has a great influence on vehicle handling stability and ride comfort.In the later stage of vehicle design,the basic parameters of the vehicle have been determined,so it is necessary to optimize the suspension rubber bushing.In this paper,a domestic car is taken as the research object,aiming at improving the handling stability and ride comfort of the whole vehicle,and optimizing the shape of the suspension rubber bushing at the key part of the vehicle,the following research contents are specifically carried out:Firstly,the static and dynamic behavior of the suspension rubber bushing is studied,and the mechanical characteristic curve of the suspension rubber bushing at the key part of the whole vehicle is obtained.The mathematical model of a typical suspension rubber bushing is selected,and the mathematical model parameters are fitted through the above mechanical characteristic curve to obtain a complete suspension rubber bushing mathematical model.Secondly,the FORTRAN language is used to program the suspension rubber bushing mathematical model through the GFOSUB user subroutine,waiting for the multibody dynamics software Adams/Car to call.The flexible body of the control arm under the MacPherson suspension and the torsion beam suspension is built,the front and rear suspensions and other subsystems are assembled,and the rigid-flexible multi-body dynamics model of the whole vehicle is finally established.The steady-state rotation test and the serpentine test were selected as the typical tests for handling stability.The random uneven road surface simulation test was selected as the typical test of ride comfort,and the vehicle handling stability and ride comfort simulation was carried out and the advantages and disadvantages were analyzed.Thirdly,using the suspension hard point and rubber bushing mathematical model parameters as the analysis variables,the vehicle handling stability and ride comfort evaluation index as the objective function,carrying out the sensitivity analyze for each hard point and mathematical model parameters combined with Adams/Car and Isight multi-objective optimization system.Taking the performance index of poor vehicle handling stability and ride comfort as the optimization target,the high sensitivity of the suspension hard points and rubber bushing mathematical model parameters as the optimization variables.the second-generation non-dominated sorting multi-objective optimization genetic algorithm(NSGA-II)was selected as the algorithm,which is optimized to obtain the ideal suspension hard points and rubber bushing mathematical model parameters.Finally,taking the inner and outer diameters of the suspension rubber bushing as the optimization variables,the ideal suspension rubber bushing mathematical model parameters are used as the optimization target,and NSGA-II is selected as the optimization algorithm,combined with the multi-objective optimization system Isight and the finite element analysis software Hypermesh,Abaqus to optimize the shape of the suspension rubber bushing to finally obtain the shape of the suspension rubber bushing with ideal mechanical properties.