A Study On The Dynamic Damping Characteristics Of A High-speed Train Hydraulic Damper

The hydraulic damper is the damping component in the suspension system of railway vehicles,its dynamic damping characteristics play a key role in the running stability and comfort of railway vehicles,it is of great significance to study the dynamic damping characteristics of the hydraulic damper and its influencing factors for optimizing the product design of the hydraulic damper and improving the dynamic performance of the vehicle.Taking the hydraulic yaw damper used in a high-speed train in China as the research object,the limitations of the conventional macro theory of the dynamic damping characteristics of the hydraulic damper are analyzed,based on the modeling and analysis of the static stiffness characteristics of the hydraulic damper,a detailed parametric model describing the dynamic damping characteristics of the hydraulic damper is established.Based on the established parametric model,the dynamic damping characteristics of the hydraulic damper are simulated by MATLAB software,and the simulation results are compared with the bench test results of the hydraulic damper.The results show that the indicator diagram of the damper at various speeds has good consistency,the maximum relative error of the key damping characteristics is only 2.6 percent,and the asymmetry rate is close to and the maximum value is only 2.45 percent,so the parameterized model of the dynamic damping characteristics of the hydraulic damper has high accuracy.Based on the obtained parametric model,the effects of the key excitation parameters and structural parameters on the dynamic damping characteristics of the hydraulic damper are studied,the results show that:(1)Generally speaking,the amplitude variation characteristics of dynamic stiffness and dynamic damping rate are decreasing curves,the frequency variation characteristics of dynamic stiffness show a weak increasing trend,while the frequency variation characteristics of dynamic damping rate show a strong decreasing trend.(2)When the rubber attachment stiffness increases,the dynamic stiffness,dynamic damping rate and phase angle of the hydraulic damper first increase and then tend to be stable;when the dissolved air in oil increases,the dynamic stiffness,dynamic damping rate and phase angle of the hydraulic damper gradually decrease,among which the phase angle decreases most obviously;in general,increasing the piston area is conducive to improving the dynamic damping characteristics of the hydraulic damper,but in practice,it is often due to the constraints of structure and installation space,the increase of pressure cavity caused by other parameters is generally not conducive to the dynamic damping characteristics;with the increase of leakage between the piston and the inner tube,the dynamic stiffness and dynamic damping rate of hydraulic damper decrease.The parameterized model and analysis results of the dynamic damping characteristics of the hydraulic damper obtained in this paper are of great significance and reference value to guide the dynamic design of high-speed train hydraulic damper products.