A comprehensive investigation into the vibration fatigue characteristics of safety hangers for metro vehicles

Abstract To meticulously investigate the reasons behind the cracking of the safety crane in a subway vehicle, we conducted a comprehensive analysis of its modes and conducted mode tests accordingly. These tests revealed the natural frequencies of the crane to be approximately 340 Hz and 990 Hz. Additionally, to gain insights into the acceleration and dynamic stress levels experienced by the safety crane during operation, we conducted a line tracking test on the vehicle. Analysis of the test data revealed that the acceleration and dynamic stress of the crane exhibited significant energy levels around 340 Hz, indicating that the first-order mode was excited, resulting in resonance. A comparative evaluation of the fatigue data of dynamic stress, both before and after rail grinding, revealed that the fatigue damage caused by rail wave grinding significantly shortened the service life of the safety crane.