Viability of the Application of Acoustic Emission (AE) Technology for the Process and Management of Maintenance in Industries: Defect Detection, On- Line Condition Monitoring, Diagnostic and Prognostic Tools Shuib Husin 1 , D.Mba 2 and R.I. Raja Hamzah 3 Abstract--- This paper reviews the success of the application of Acoustic Emission (AE) technology in rotating elements which can be adopted as a tool for the maintenance strategy, “Condition Based Maintenance”. Preventive maintenance needs data to be supplied in order to plan the maintenance schedule. On-line condition based monitoring offered by AE technology, provides a complimentary assessment of the current condition of machines whereby outage schedules can be planned for proactive maintenance. Research into the feasibility and viability of AE technology at Cranfield University, which was started in 1984, on rotating elements has shown encouraging results and it is evident that AE technology can be employed as a tool for defect detection, on-line condition monitoring, diagnosis and prognosis. All these capabilities of AE are of benefit to the process and management of maintenance in industries. Keywords: Acoustic Emission (AE), Condition Based Maintenance (CBM), Condition Monitoring, Defect Detection. I. Introduction: AE Technology as a Special Tool to Complement theProcess and Management of Maintenance Employing special tools for maintenance purposes in anticipating and heading off failures significantly contributes to improving reliable plant capacity in industry [1]. It leads to the effective implementation of proactive work whereby attention would be given to preventive and predictive maintenance. Vibration analysis and acoustic emission (AE) technology are among the special tools that are being referred for the process and management of maintenance. ___________ 1 Universiti Kuala Lumpur Malaysian Spanish Institute , Department of Mechanical Engineering, Kulim Hi-Tech Park, 09000 Kulim, Kedah, Malaysia. 2 Cranfield University, School of Engineering, Cranfield, Beds MK43 0AL, UK. 3 University Teknologi Malaysia, Appplied Mechanics Dept, UTM, JB, Malaysia. Corresponding author. Fax: +44(0) 1234 754681 E-mail address: d.mba@cranfield.ac.uk The vibration technique has been reported widely in its use and is well established as a diagnostic technique for rotating machinery in industry compared with AE which is still in its infancy [2]-[5]. However, a numbers of researches show that vibration analysis is incapable of early fault detection [6]- [8], [11]. The application of AE technology as a diagnostic tool for rotating elements, particularly gears and bearings, is now get attention in maintenance system based on its capabilities in early fault/defect detection, on-line and condition monitoring, and diagnosis and prognosis which is noted better over vibration analysis. Comparative work between vibration techniques, AE and spectrometric oil analysis was done by Tan (2005) in his thesis programme and can be found in Tan et al., (2005). The capability to detect and indicate the incipient defect and defect size progression by AE technology allows the maintenance people to monitor the rate of degradation on the rotating elements. In that aspect, it is unachievable using vibration analysis [4], [6], [7], [9]-[12] Based on the encouraging results of the employment of AE technology on side and test-rigs, it is concluded that AE technology offers a complementary tool for defect detection and is viable in the condition monitoring of rotating elements; gears, bearings and shaft seals [4]. Furthermore, it is gaining acceptability as a diagnostic tool. Active-observing benefits from the on-line monitoring technique offered by AE technology; for instance, it provides early warnings of serious equipment problems. It is interesting to note that the term “diagnosis and prognosis” used in machinery maintenance has always been referred to as the effort required in detecting and understanding of incipient defects/problems of a machine‟s parts which later might cause a casualty or catastrophic failure. Gears and bearings have a high risk of problems which affect a machine‟s performance and safety, and eventually cause money loss. They are widely used in the gearbox and transmission of various engineering systems. Proceedings of the International MultiConference of Engineers and Computer Scientists 2010 Vol III, IMECS 2010, March 17 - 19, 2010, Hong Kong ISBN: 978-988-18210-5-8 ISSN: 2078-0958 (Print); ISSN: 2078-0966 (Online) IMECS 2010