A joint vibro-acoustic method for periodic track short-wave defect identification

Abstract

The present track short-wave irregularity inspection and evaluation method, based on the vibration signals collected by accelerators mounted on the axle box of high-speed comprehensive inspection train, is relatively a proven technology. However, with data analysis and check on-site, it finds out that the periodic defects exist in the sections where the dynamic responses are weak. When vibration signals are used for short-wave analysis, it may have the problems of inaccurate frequency identification, lack of energy concentration, etc., which is easy to cause missing or misjudgment of defects. As a result, the stability and robustness of present method need to be enhanced and refined. This article analyzes measured acoustic signals for a supplement to vibration signals. Based on vibration signals of axle box and acoustic signals collected by microphones mounted on the bogie frame of high-speed comprehensive inspection train, a new joint vibro-acoustic method for periodic track short-wave defect identification is proposed. The vibration and acoustic signals are processed and evaluated by Adaptive Chirp Mode Decomposition (ACMD), Gini Index (GI) and modal recombination. Energy Factor of Vibration Mode (EVM), Energy Factor of Acoustic Mode (EAM) and Energy Factor of Vibro-acoustic Mode (EVAM) are introduced for evaluating the periodic component in signals. By analyzing three groups of signals, it proves that, combining vibration and acoustic signals, the energy concentration of periodic components can be enhanced without losing the information of other signal components, and the periodic track short-wave defects can be effectively identified.