Nonlinear vibration characteristics of railway turnout switch panel: experimental and explicit FE investigation of switch rail-baseplate contact and connection component effects
摘要
Switch panels in railway turnouts are critical for route transitions, but their complex nonlinear behavior complicates vibration analysis. This study integrates hammer testing with an explicit LS-DYNA finite element model to compute frequency response functions and systematically assess sensitivity to modeling parameters (mesh, excitation points, hourglass control, damping). Results show that including nonlinear baseplate contact is essential for capturing the dynamic response in the 300 – 1500 Hz range; without it, simulated resonance peaks shift and attenuate. A fundamental frequency bifurcation around 50 Hz is observed, triggered by coupling between locking devices and railhead contact beyond baseplate #12.5. This interaction intensifies nonlinear effects above 500 Hz. Additionally, iron blocks suppress vibrations below 500 Hz, while fillers limit vibration transmission to one sleeper span and reduce high-frequency peaks above 1500 Hz. Operating deflection shape analysis reveals dominant resonant wavelengths and baseplate deformation modes, with significant deviations from linear behavior above 576Hz due to contact nonlinearities. This explicit finite element approach effectively simulates impact dynamics, providing valuable insights for fatigue prediction and turnout design optimization.