LAUSR

Abstract High-speed, light-weight and high-load gearing is widely used in the transmission systems of modern aero-engines. Some dynamic phenomena, such as the traveling wave resonance, can be more easily encountered. It generally occurs quite suddenly and causes catastrophic accidents. This study presents an experimental investigation of the signal characteristics of the gear fatigue fracture process caused by the traveling wave resonance. The acoustic waveguide system and the dynamic calibration system are developed. The traveling wave resonance monitoring test and the fatigue performance test of the central drive bevel gear in an aero-engine are carried out. The results show the traveling wave resonant frequency and rotational speed of the driven bevel gear are identified and monitored effectively by the acoustic waveguide system. The dangerous rotational speeds range and the sound pressure energy radiated of the vibration are discussed. The results reveal the gear resonant phenomena are narrow rotational speed band sensitivity and more dangerous at high speed. The fracture mode of the driven bevel gear of aero-engine is reproduced. When the gear has initial defects and works within the dangerous rotational speed of the traveling wave resonance, the gear fatigue fracture will occur quickly. The harmonic frequency, the frequency of forward traveling wave (FTW) and backward traveling wave (BTW), and their combination frequency will appear alternately in the noise spectrum of the gear before fatigue fracture.