Cracking Faults in Grounding Terminals of a Specific Metro Train Model

［Objective］Frequent cracking faults are observed in the grounding terminals of a specific metro train model during operation. Therefore, it is essential to analyze the grounding terminal cracking causes of the train in the above case. ［Method］Line tests are conducted on faulty sections. Through collecting vibration acceleration and stress signals from relevant components, the time-frequency characteristics of different signals are studied, and the grounding terminal cracking causes are analyzed. Through analyzing the dynamic stress variations of the grounding terminals with different bracket and cable cross-section combinations, the compatibility of various structural cable brackets is evaluated. Terminal bracket selection schemes of three positions (grounding shaft end, speed shaft end, and anti-slip shaft end) are analyzed. ［Result & Conclusion］Under identical external loads, the short-arm brackets exhibit lower stress levels. The new grounding terminals demonstrate superior structural design compared to the original grounding terminals, and the fatigue life of the former is higher than that of the latter.