Research on dynamic performance and influence of new mesh-hole elastic pads for railway fasteners in an extremely cold environment

Abstract

In order to research the dynamic properties of elastic pads for a new pattern mesh-hole in an extremely cold environment, a three-dimensional finite element model of a mesh-hole rail pad is established. The Mooney-Rivlin constitutive model is used to simulate the mechanical properties of rubber materials at different temperatures, and the temperature-dependent characteristics of dynamic stiffness and damping coefficients of the mesh-hole rail pads are analyzed. Based on the vehicle-track coupling dynamic theory, the driving safety and stability properties of the rail pads at extremely cold climate are calculated and analyzed, and the applicability of the mesh-hole rail pads in the extremely cold environment is further evaluated. The research conclusions are as follows. The mesh-hole rail pads have significant low-temperature sensitivity. Namely, above −10°C, the dynamic stiffness and damping coefficients of rail pads are stable, while below this temperature, the dynamic stiffness and damping coefficients of elastic pads increase rapidly. The mesh-hole rail pad has an obvious influence on the dynamic performance of a vehicle-track system when the temperature changes. Namely, the wheel-rail force and wheel load reduction rate increase rapidly with the decrease in temperature, while the vertical dynamic displacement of the rail decreases. Under the extremely cold climate, the wheel load reduction rate of a high-speed passenger vehicle increases sharply, so the method for reducing train speed should be adopted to ensure the safety of train operation.