Energy Analysis Distribution Regarding the Crack Size in a Rotating Shaft

Abstract

Maintenance is critical to avoid catastrophic failures in rotating machinery, and detection of cracks plays a critical role because they can origin failures with costly processes of reparation, especially in shafts. The main issue in the design of intelligent systems for machine monitoring and fault diagnostics is the suitable selection of a pattern which represents the condition of the machine. Discrete Wavelet Transform, and one of its recursive form, called Wavelet Packet Transform, provides a high potential for pattern extraction. Several factors must be selected and taken into account in the wavelet transform application such as the level of decomposition, the suitable mother wavelet and the frequency bands. In this work, a rotating shaft, in which several levels of crack are induced, is analyzed looking for the main changes in energy. Changes in energies computed by means of the Wavelet Transform can be used for crack detection.