Cyclostationarity applied to acoustic emission and development of a new indicator for monitoring bearing defects

Department of Mechanical Engineering, École de Technologie Supérieure, 1100, Notre-Dame street West, Montreal, H3C 1K3, Quebec, Canada

^a Corresponding author: marc.thomas@etsmtl.ca

Received: 17 June 2013
Accepted: 15 May 2014

Abstract

The exploitation of cyclostationarity properties of vibratory signals is now more widely used for monitoring rotating machinery and especially for diagnosing bearing defects. The acoustic emission (AE) technology has also emerged as a reliable tool for preventive maintenance of rotating machines. In this study, we propose an experimental study that characterizes the cyclostationary aspect of acoustic emission (AE) signals recorded from a defective bearing (40 μm on the outer race) to see its efficiency to detect a defect at its very early stage of degradation. An industrial sensor (UE10 000) is used. An electrical circuit converts the high frequency signal into an audible signal by heterodyning. The cyclic spectral density, which is a tool dedicated that put into evidence the presence of cyclostationarity, is used for characterizing the cyclostationary. Two new indicators based on this cyclostationary technique are proposed and compared for early detection of defective bearings.