Simulation and experimental investigation on dynamic response characteristics of rail connection components

Abstract

To investigate the dynamic mechanical responses of rail connection components for high-speed railways, a combined numerical simulation and experimental method was adopted in this study. The deformation and stress distribution characteristics of components under typical loading conditions including longitudinal force and rolling force were analyzed. Modal analysis and fatigue life tests were performed on serpentine springs, and four structural schemes with different cross-sectional sizes (DR_1-DR_4) were designed. The effects of cross-sectional parameters on impact response, natural frequency and stiffness evolution were comprehensively studied. Through comparative analysis of multiple schemes, the regulation mechanism of wall thickness and cross-sectional dimension on the dynamic performance of serpentine springs was revealed, and the design defect of blindly increasing cross-sectional sizes was avoided. The results demonstrated that the overall deformation of rail connection components was dominated by serpentine springs, and high-stress concentration zones were distributed at the curved segments of springs. The first six-order natural frequencies of serpentine springs were confined to the range of 500-750 Hz, and the resonance risk was extremely low under normal service conditions. The inner sides of curved sections were confirmed as the weak areas prone to fatigue failure. The optimal matching state between stiffness and mass was realized by the DR_1 scheme, which exhibited the most stable impact response and the mildest stiffness variation, as well as the best comprehensive performance. The obtained findings were provided as sufficient theoretical foundations and experimental supports for the structural optimization, fatigue life assessment and engineering application of rail connection components.