| As one of the main components of the automobile suspension system,the shock absorber has the complex damping non-linear characteristics,which has an important influence on the handling and ride comfort of the automobile.Therefore,an accurate parametric model of shock absorber is established to analyze the characteristics of the shock absorber and to study the influence of the shock absorber characteristics on the ride comfort of the vehicle,which is of great significance to the development and design of the shock absorber and improve the ride comfort of the vehicle.In this paper,for a developing vehicle,firstly,the structure characteristics and working principle of the shock absorber are introduced.In order to establish the precise shock absorber model,based on the beam deflection theory and the large deformation theory of circular thin plate,the hybrid solutions of the deflection of the single plate and multiple plates of the shock absorber are proposed,and the correctness of the proposed hybrid solutions is verified by the numerical simulation.Then based on the principle of fluid mechanics,combined with the deflection of the valve plate obtained by the hybrid method,the theory model and the AMESim model of the shock absorber are established,and the correctness of the models is verified by the bench test of shock absorber,on this basis,the influence of the key structure parameters and property parameters of the shock absorber on its damping characteristics is analyzed.Secondly,in view of the problem that the vibration system model widely used in the study of vehicle ride comfort has less consideration on the influence of the bushings of shock absorber strut assembly,the multi-degree of freedom theoretical model of the vehicle with the shock absorber strut assembly bushings is established,and the vehicle ride comfort is analyzed by combining the established parametric model of shock absorber,compared with the theoretical model without the corresponding bushings,it is found that the bushings of the strut assembly of shock absorber have a certain influence on the ride comfort of the vehicle,and they should not be neglected when establishing the model of the vehicle vibration system.In order to compare with the theoretical model,the models of the vehicle subsystems are established by ADAMS/Car,and the model of suspension system which has a great influence on ride comfort in each subsystem model is validated by test data,based on this,the virtual prototype model of the vehicle is established and the ride comfort simulation is carried out.The simulation result is in good agreement with the theoretical result,which shows that the multi-degree of freedom theoretical model of the vehicle established in this paper is correct and reliable,and can be used to study the ride comfort of the vehicle.Finally,based on the established theory model of the vehicle,it is analyzed that the influence of damping characteristics of shock absorber and stiffness of shock absorber strut assembly bushings on the ride comfort of the vehicle,and on this basis,in order to improve the ride comfort of the vehicle,the key structural parameters of shock absorber and the stiffness of bushings which has great influence on ride comfort are optimized and designed by genetic algorithm.By comparing and analyzing the vertical vibration of the car body before and after optimization,it is shown that optimizing the performance of shock absorber strut assembly can effectively improve the ride comfort of the vehicle.In summary,in the paper,the characteristics of the shock absorber is mainly analyzed,the vehicle ride comfort is studied by combining the model of the shock absorber and the multi-degrees of freedomt heory model of the vehicle.The method adopted in this paper can be used to predict the damping characteristics of the shock absorber,and it can also be used for the development and design of the shock absorber assembly with the overall objective of vehicle performance requirements.The research result provides some reference for the design and development of hydraulic shock absorber and reasonable match between the characteristics of shock absorber strut assembly and the dynamic performance of vehicle. |
PDF Full Text Request