Air Suspension System Model Coupled With Leveling and Differential Pressure Valves for Railroad Vehicle Dynamics Simulation

Abstract

In this investigation, a nonlinear air suspension system model that accounts for the coupling between air springs, leveling valves, and differential pressure valves is developed and integrated into generalpurpose multibody dynamics computer algorithms. It is demonstrated that the proposed model can capture highly nonlinear air suspension characteristics resulting from the coupling with leveling and differential pressure valves, and good agreements are obtained between the numerical and ontrack test results. Furthermore, the effect of flow characteristics of leveling valves on the wheel load unbalance on spiral curve sections is discussed. The numerical results obtained by the proposed model clearly indicate the importance of modeling the nonlinear flow characteristics of the leveling and differential pressure valves for assessing the vehicle safety in low speed operations on a small radius curved track.