Simulation and analysis of stick-slip vibration characteristics of brake discs for high-speed trains

To investigate stick-slip vibration between high-speed train brake discs and pads, a three-dimensional finite element model was developed in Abaqus using actual disc dimensions (brake disc material: 25Cr2MoVA; pad and backing plate material: copper-based powder metallurgy), simulating time-domain responses under various braking conditions via transient analysis. The stick-slip behavior of the brake pad was analyzed in the circumferential and radial directions at different positions, revealing the specific process on the contact surface. The vibration behavior of circular, triangular, and hexagonal brake pads at different angular velocities was compared to determine the optimal pad shape for suppressing stick-slip vibration. Circumferential analysis showed a vibration intensity distribution symmetric about the backing plate's central axis, with edge-proximal amplification: 3573 mm/s and 0.040 mm displacement at the friction entry side versus 2513 mm/s and 0.025 mm at the exit side. Radially, vibration intensity increased nonlinearly toward the rotation axis. The stick-slip mechanism initiated through localized sliding and propagated to full-surface transitions within 0.2-second cycles. Comparative evaluation identified the triangular pad as optimal, showing faster convergence (critical angular velocity 7.2 vs 7.3 rad/s for circular and 7.4 rad/s for hexagonal) and lower stabilized displacement (0.072 vs 0.080 mm and 0.077 mm). The circular pad exhibited periodic vibration patterns due to axisymmetric stiffness distribution, while the hexagonal design showed transitional characteristics. This study provides a reference for suppressing stick-slip vibration in high-speed train brake discs..