Experiments on the damping characteristics of a high-speed train hydraulic damper under low-temperature conditions

Aiming at studying the low-temperature damping characteristics of hydraulic damper, experimental research in the temperature range of -50°C∼+30°C was carried out to test the dynamic damping characteristics of a Chinese CRH high-speed train hydraulic yaw damper. Research results show that damping characteristics of the hydraulic damper will vary significantly at low temperature conditions when compared with that at normal temperatures, in general cases, the Force-displacement ( F - s ) curves are distorted and the damping forces are in abnormal levels; at very low temperatures, when the excitation speed is increasing, more severe empty strokes will occur during the damper compressions, so the absorption works of the damper will decrease significantly in these cases; in addition, dynamic stiffness of the damper will increase with the decreasing of temperatures, but in the compression stroke with large excitation speed, the dynamic stiffness at very low temperature conditions will drop sharply due to empty strokes. The results obtained in this study are significant for reference to improve the environment adaptability of high-speed rail hydraulic dampers and dynamics of the train operating under extreme cold weather conditions.