Investigating fatigue behavior of gear components with the acoustic emission technique

A novel method is presented to evaluate the complicated fatigue behavior of gears made of 20Cr2Ni4A. Fatigue tests are conducted in a high-frequency push-pull fatigue tester, and acoustic emission (AE) technique is used to acquire metal fatigue signals. After analyzing large number of AE frequency spectrum, we find that: the crack extension can be expressed as the energy of specific frequency band, which is abbreviated as F-energy. To further validate the fatigue behavior, some correlation analysis is applied between F-energy and some AE parameters. Experimental results show that there is significant correlation among the F-energy, root mean square (RMS), relative energy, and hits. The findings can be used to validate the effectiveness of the F-energy in predicting fatigue crack propagation and remaining life for parts in-service. F-energy, as a new AE parameter, is first put forward in the area of fatigue crack growth.