Research On Coupling Vibration Response And Vibration Reduction Control Of Car-body And Underframe Equipment

The Speed-up and modernization of high-speed trains make the underframe equipment heavier and more complicated.Almost all the underframe equipment is designed with chassis suspension style and this kind of design will inevitably reduce the car-body bending frequency and increase the vibration of the car body.In order to reduce the influence of the underframe equipment on the vibration of the car-body,the suspension parameters and the suspension position of the underframe equipment must be reasonably selected,at the same time,to reduce the vibration of the car body,a series of vibration control techniques can be employed.Under the support of the National Natural Science Foundation of China(51375405,51775456)and the National Key Laboratory Self-funded Fund(2016TPL_T10,2019TPL_T03),this paper takes a kind of high-speed rail inspection vehicle as the study 's subject,taking the reduction of the elastic vibration of the car-body as research purpose,and taking the coupling dynamics theory as the theoretical basis.The numerical simulation model and the multi-body dynamics model are established.This paper has put forward a series of questions such as the coupling vibration of the underframe equipment and the car-body;the parameter optimization of the underframe equipment,and the vibration control of car-body,the specific research works are as follows:Firstly,the modeling process of the dynamic model of the coupling system between the car-body and the underframe equipment is introduced in detail.The numerical simulation model and multi-body dynamics model are built respectively for the different research problems.The numerical model is solved in time domain and frequency domain separately.The influence of car-body flexibility on the vertical vibration characteristics of the vehicle is studied in the time domain.In the frequency domain,the questions of stability of the system,the resonant frequency of the system,and the comparison of the acceleration power spectral density of the rigid-flexible coupled model and the multi-rigid model are analyzed.Secondly,the coupling vibration effects of the car-body and the underframe equipment are discussed.The suspension parameters of the underframe equipment are changed by the control variable method.The influence of different suspension system frequencies,suspension system damping ratio,suspension mass and suspension position are analyzed.The vibration isolation theory is used to optimize the suspension parameters,and the optimal layout scheme of the underframe equipment is proposed.The comparison between the experimental results and the numerical solutions validates the efficiency of this optimization method.Finally,three different control models are proposed for the vibration reduction of vehicle systems.They are the active and semi-active control model for structural vibration of car-body,and the structure damping control model of the car-body.The modeling process and vibration absorbing effect are discussed in detail.the research provides a certain reference for the design of vibration reduction control for high-speed trains.The research results show that,for the coupled vibration issue between the car-body and the underframe equipment,it is an effective method to establish the rigid-flexible coupled dynamics model and perform the dynamic analysis.At the same time,use the vibration reduction theory to optimize the parameters of the underframe equipment,and use the active and semi-active vibration control strategies can reduce the vertical vibration of the car-body and improve the passengers' ride comfort effectively.