Browsing by Author "Tan, Chee Keong"

Now showing 1 - 8 of 8
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    Application of acoustic emission to seeded gear fault detection
    (Elsevier Science B.V., Amsterdam., 2005-01-01T00:00:00Z) Toutountzakis, Tim; Tan, Chee Keong; Mba, David
    Acoustic emission (AE) is gaining ground as a non-destructive technique for health diagnosis on rotating machinery. There are vast opportunities for development of the AE technique on various forms of rotating machinery, including gearboxes. This paper reviews some recent developments in application of AE to gear defect diagnosis. Furthermore, an experimental investigation that examines the effectiveness of AE for gear defect identification is presented. It is concluded that application of the AE technique to seeded gear defect detection is fraught with difficulties. In addition, the viability of the AE technique for gear defect detection from non-rotating components of a machine is called into question.
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    A comparative experimental study on the diagnostic and prognostic capabilities of acoustics emission, vibration and spectrometric oil analysis for spur gears.
    (Elsevier Science B.V., Amsterdam, 2007-01-01T00:00:00Z) Tan, Chee Keong; Irving, Phil E.; Mba, David
    Prognosis of gear life using the acoustic emission (AE) technique is relatively new in condition monitoring of rotating machinery. This paper describes an experimental investigation on spur gears in which natural pitting was allowed to occur. Throughout the test period, AE, vibration and spectrometric oil samples were monitored continuously in order to correlate and compare these techniques to natural life degradation of the gears. It was observed that based on the analysis of root mean square (rms) levels only the AE technique was more sensitive in detecting and monitoring pitting than either the vibration or spectrometric oil analysis (SOA) techniques. It is concluded that as AE exhibited a direct relationship with pitting progression, it offers the opportunity for prognosis.
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    Correlation between Acoustic Emission activity and asperity contact during meshing of spur gears under partial elastohydrodynamic lubrication.
    (Springer Science Business Media, 2005-09-01T00:00:00Z) Tan, Chee Keong; Mba, David
    This paper presents results of an experimental programme that suggested a correlation between levels of Acoustic Emission (AE) activity and the frictional resistance of contacting asperities of spur gears under partial elastohydrodynamic lubrication.
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    Diagnostics and prognostics with acoustic emission, vibration and spectrometric oil analysis for spur gears; a comparative study
    (Learned and Professional Society Publishers, 2005-08-01T00:00:00Z) Tan, Chee Keong; Irving, Phil E.; Mba, David
    Whilst vibration and spectrometric oil analysis for gear fault diagnosis are well established, the application of AE to this field is still in its infancy. This paper describes an experimental investigation on spur gears in which natural pitting was allowed to occur. Throughout the test period, AE, vibration and spectrometric oil samples were monitored continuously in order to correlate and compare these techniques to natural life degradation of the gears. It was observed that the AE technique was the most sensitive in detecting and monitoring pitting.
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    Further improvement of fluidized bed models by incorporating zone method with aspen plus interface
    (Elsevier, 2017-06-01) Hu, Yukun; Wang, Jihong; Tan, Chee Keong; Sun, Chenggong; Liu, Hao
    While providing a fast and accurate tool of simulating fluidized beds, the major limitation of classical zero-dimensional ideal reactor models used in process simulators, such as models built into commercial software (e.g. Aspen Plus®), has been the difficulties of involving thermal reciprocity between each reactor model and incorporating heat absorption by the water wall and super-heaters which is usually specified as model inputs rather than predicted by the models themselves. This aspect is of particular importance to the geometry design and evaluation of operating conditions and flexibility of fluidized beds. This paper proposes a novel modelling approach to resolve this limitation by incorporating an external model that marries the advantages of zone method and Aspen Plus in a robust manner. The improved model has a relatively modest computing demand and hence may be incorporated feasibly into dynamic simulations of a whole power plant.
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    Identification of the acoustic emission source during a comparative study on diagnosis of a spur gearbox
    (Elsevier Science B.V., Amsterdam., 2005-05-01T00:00:00Z) Tan, Chee Keong; Mba, David
    Condition monitoring of gears with vibration analysis is well established whilst the application of acoustic emission (AE) to gear defect diagnosis and monitoring is still in its infancy. This paper details results of an experimental programme to ascertain and validate the applicability of AE to seeded gear defect identification. Furthermore, comparisons are made to vibration diagnosis. As a direct consequence of the experimental programme, the relationship between temperature, oil film thickness and AE activity were investigated. It is shown that similar to the lubricant film thickness between non-conforming surfaces under isothermal conditions, AE activity is not influenced by load. Limitations of applying AE to seeded defect identification are presented and it is concluded that the source of AE activity is attributed to asperity contact.
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    An investigation on the diagnostics and prognostic capabilities of acoustic emission (AE) on a spur gearbox
    (Cranfield University, 2005-08) Tan, Chee Keong; Irving, Phil E.; Mba, David
    The aim of this research project is to explore a new technique, Acoustic Emission (AE), on both the diagnostic and prognostic capabilities in monitoring gear teeth degradation (pitting), and compare with the more widely used techniques such as vibration monitoring and Spectrometric Oil Analysis (SOA). Furthermore, by employing the experimental results and past literature, a model in predicting the amount of gear surface pitting wear using AE activity level was proposed. The successful forinulation of this proposed model may be able to predict the remaining life of the gear after pitting has been detected, thereby allowing timely replacement to be carried out without the risk of catastrophic failure. A series of experimental tests which include seeded defect simulations, study on the effect of operating parameters over AE (under isothermal conditions), AE source determination tests and accelerated gear fatigue tests have been performed to investigate the diagnostics and prognostics capabilities of AE via a back-to-back gearbox set up. The experimental results achieved have highlighted some significant findings: (a) The variation in rotating speeds, change the AE levels in a much significant amount as compared to the same variation in applied load. (b) The prime source of AE was postulated to be asperity contact under rolling and sliding of the meshing gear teeth surfaces. (c) AE technique has a far better degradation (pitting) monitoring capability compared to vibration and SOA techniques. These findings have made a vast contribution in condition monitoring of gearbox using AE technique and the proposed model has also offered opportunity to make AE a potentially viable and effective tool in diagnosis and prognosis of gearbox or even other rotating machinery defects.
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    Limitation of Acoustic Emission for Identifying Seeded Defects in Gearboxes
    (Springer Science Business Media, 2005-03-01T00:00:00Z) Tan, Chee Keong; Mba, David
    Acoustic Emissions (AE) is gaining ground as a Nonestructive Technique (NDT) for health diagnosis on rotating machinery. Vast opportunities exist for development of the AE technique on various forms of rotating machinery, including gearboxes. This paper reviews recent developments in application of AE to gear defect diagnosis. Furthermore, experimental results are presented that examine and explore the effectiveness of AE for gear defect diagnosis. It is concluded that application of AE to artificially seeded gear defect detection is fraught with difficulties, particularly for fault identification. In addition, the viability of the AE technique for gear defect detection by making observations from nonrotating components of a machine is called into question. Nevertheless, guidance is offered on applying the technique for monitoring the natural wear of gears.