Abstract: The shaft crack is one of the main serious malfunctions that often
occur in rotating machinery. However, it is difficult to locate the crack and
determine the depth of the crack. In this paper, the acoustic emission (AE)
signal and vibration response are used to diagnose the crack. The wavelet
transform is applied to AE signal to decompose into a series of time-domain
signals, each of which covers a specific octave frequency band. Then an
improved union method based on threshold and cross-correlation method is
applied to detect the location of the shaft crack. The finite element method is
used to build the model of the cracked rotor, and the crack depth is identified
by comparing the vibration response of experiment and simulation. The
experimental results show that the AE signal is effective and convenient to
locate the shaft crack, and the vibration signal is feasible to determine the
depth of shaft crack.
