Analysis of the effect of wheel-rail high-frequency excitation on brake disc vibration of high-speed trains

In order to investigate the influence of high-frequency wheel–rail excitation on the vibration of brake discs in high-speed trains, a rigid–flexible coupled vehicle–track dynamics model was established, incorporating multiple flexible components such as rails, wheelsets, and brake discs. Analyses were conducted in both time and frequency domains. The model introduced measured spectrum of the Wuhan to Guanghzou high speed railway, rail corrugation, and wheel polygonal excitation to systematically explore the effect mechanism of wheel–rail excitation on brake disc vibration. Furthermore, vibration characteristics under the coupled action of emergency braking and wheel–rail excitation were studied. The results show that under various wheel–rail excitations, the vertical vibration response of the end brake disc is more significant than that of the intermediate discs disc. Specific wheel polygonal orders (mainly 18th and 24th orders in the transverse direction and 24th order in the vertical direction) induce intense vibration, with transverse vibration being most pronounced at a wave depth of 0.05 mm. Under combined emergency braking and wheel–rail excitation, the flexible brake disc model reflects vibration characteristics more accurately than the rigid model, while the transverse clamping force from the brake caliper effectively suppresses transverse vibration. Given the broadband nature of wheel–rail interaction and continuous speed variations during operation, completely avoiding resonance is challenging. However, optimizing the brake disc structure or controlling the train speed through excitation sections can significantly mitigate resonance risks. This study provides a reference for the structural design and vibration control of brake discs in high-speed trains.