Simulation of vehicle-turnout coupled dynamics considering the flexibility of wheelsets and turnouts

The turnout causes significant vibrations of the wheel-rail system. In this study, based on the modal superposition method and finite element method, the flexibility of wheelsets and turnouts is considered respectively, and the vehicle-turnout coupled dynamic model is established. The swept-frequency analysis is adopted to capture the natural frequencies of wheelsets and turnouts. The dynamic interaction and modal resonance performance of the wheel-rail system are investigated when the vehicle passes through the turnout. Results indicate that during the wheel load transition in the crossing, the major frequency bands of the vertical wheel-rail impact force are related to natural frequencies of the crossing. Due to the wheelset resonant modes, the vertical impact force decreases by 12% in the through route and increases by 10% in the diverging route. The wheelset flexibility affects the wheel-rail creepage and decreases the longitudinal wheel-rail force. The wheel-rail impact force has nearly converged as the cut-off frequency of wheelsets reaches 500 Hz. The dominant frequencies of axle-box and rails' vibrations correspond to the modal resonance between the bending modes of wheelsets and the crossing in the vertical direction, as well as, the wheelset's umbrella mode and the crossing's pinned-pinned mode in the lateral direction.