Dynamic Response of Bogie in Failure Modes of High-Speed EMU Air Spring

In order to simulate the failure states of a high-speed EMU's air spring, a 3D coupled dynamics model of the air spring system was established by the theory of pneumatics and the function fitting method. A co-simulation by combination of the 3D coupled model of air spring and the vehicle MBS dynamics model of EMU was carried out to study the dynamics response of the high-speed EMU bogie in the failure modes of air spring. The results of air spring leakage analysis show that the possibility of the vehicle instability caused by the leakage of air spring is little, but the leakage will cause the ride comfort to deteriorate. The peak values of vehicle vertical and horizontal safety indexes appear when the leakage area is 15 mm2 and 30 mm2, respectively. The action of the differential pressure valve can effectively guarantee the vehicle dynamics performance in the air spring leakage process. The results of vehicle curving performance analysis show that, if the direction of the vehicle passing a curve is consistent with the leakage side of the air spring, the wheel load reduction rate is about 20% higher than that on a straight track. The failure of the differential pressure valve and the leveling valve will affect the vehicle dynamics performance to some extent, but the dynamics indexes can still meet the safety requirement.