Study on the Influence of Dynamic Performance of Rail Pad on the Vibration Characteristics of E-type Fastener Clip

The issue of E-type fastener clip fracture due to high-frequency vibration has attracted widespread attention, with research focusing on the mechanisms leading to such failures. The rail pad, crucial to the fastener system for elastic vibration damping elastic vibration damping, exhibits significant variations in dynamic performance depending on the material and structure. Currently, there is a lack of studies on how the dynamic performance of the rail pad affects E-type fastener clip vibrations and fractures. To address this, the tests for the dynamic stiffness of rail pads under constant frequency and variable temperature conditions have been conducted using a universal testing machine fitted with a temperature control box, revealing its wide-band dynamic characteristics. These characteristics were represented using the Prony series. A detailed finite element model of the fastener system was developed, incorporating the nonlinear contact relationships among the components and the dynamic performance of rail pads. Frequency response analysis was performed to compare the dynamic steady-state responses of fastener systems with different rail pads. Finally, drop shaft impact tests were simulated to evaluate the vibration acceleration response of E-type fastener clip with various rail pads. The results indicate that the dynamic performance of rail pad significantly affects the vibration characteristics of E-type clips. Among the three rail pads with identical stiffness, the new mesh-type rail pad (NMTRP) demonstrated the best damping energy absorption capability, effectively reducing the vibration acceleration of the E-type Fastener clip.