Natural mechanical degradation measurements in slow speed bearings

Abstract

Acoustic Emission (AE) technology applied to condition monitoring is gaining acceptance as a useful complimentary tool. This paper demonstrates the use of AE measurements to detect, monitor the growth and locate natural defect initiation and propagation in a conventional rolling element bearing. To undertake this task a special purpose test-rig was built to allow for accelerated natural degradation of a bearing race. It is concluded that crack initiation and its subsequent propagation is detectable with AE technology. The paper also investigates the source characterisation of AE signals associated with a defective bearing whilst in operation.

A review of diagnostics and prognostics of low-speed machinery towards wind turbine farm-level health management

“…Acoustic emission (AE) is transient elastic waves that are generated by a rapid release of energy from localized sources within a material when it is subjected to mechanical or thermal stresses at a certain level [37,38]. The typical frequency of AE signals is within 100 kHz and 1 MHz [38].…”

Robust condition monitoring of rolling element bearings using de-noising and envelope analysis with signal decomposition techniques

“…Elforjani & Mba, 2009). To record AE signals, a wideband frequency acoustic emission sensor, WSα, is exploited in this study.…”

A Probabilistic Approach to Small Fatigue Crack Initiation and Sizing Using Acoustic Emission

“…They investigated how low amplitude bursts in a short duration of time in Region I correspond to micro-cleavage in thermally aged steel plates. Rahman, et al [10] and Mba [11], hypothesized that a sudden and significant increase in AE events corresponds to damage initiation. Rahman [10] offered that significant increase in hit count data might correspond to incipient damage due to wear in rolling elements during their contacts.…”

“…Rahman [10] offered that significant increase in hit count data might correspond to incipient damage due to wear in rolling elements during their contacts. Mba [11] presented result of their experimental investigation for detecting natural crack in slow speed shafts.…”