Failure analysis on the brake disc hubs with fatigue cracks caused by wheel polygonization

The brake disc hubs of high-speed trains have encountered cracking issues. This study aims to analyze the causes of these failures. Field tests were conducted to obtain stress and acceleration data from the rotating brake discs using telemetry equipment. The analysis ultimately determined that wheel polygonization is the root cause of the cracks in the brake disc hubs. By integrating the theories of elasticity mechanics and P1 force, the relationship between brake disc stress, vibration acceleration, and wheel polygonization was established. This study establishes a threshold for the polygonal amplitude to prevent early failures. The findings offer novel insights and practical maintenance solutions to enhance the durability and operational safety of high-speed train components.