Evaluation of Bridge Noise Increase Due to Wheel Local Wear

Abstract

Local wear, the length of which in the circumferential direction is relatively long, occurs occasionally on a railway wheel tread. Wheels with the local wear induce increase of bridge noise when they run at high speeds. Through the measurements of wheel roughness, the depth and the width of the wear are found to be up to 0.5 mm and about 300 mm mostly, respectively. The roughness spectra of the wheels show that roughness level below 20 m^-1 in spatial frequency is increased due to local wear. The measured results in the field test indicate that bridge noise and associated vibration increase where the index values estimated from roughness spectra is greater than about 20 dB (corresponding to the wear depth of about 0.1 mm). It is found that the bridge noise and associated vibration level is increased by local wear in the frequency range of 80 Hz to 800 Hz at the train speed of 313 km/h.