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Lin T.R.,Cooperative Research Center for Infrastructure and Engineering Asset Management | Lin T.R.,Queensland University of Technology
Journal of Sound and Vibration | Year: 2012

An analytical solution is presented in this paper for the vibration response of a ribbed plate clamped on all its boundary edges by employing a traveling wave solution. A clamped ribbed plate test rig is also assembled in this study for the experimental investigation of the ribbed plate response and to provide verification results to the analytical solution. The dynamic characteristics and mode shapes of the ribbed plate are measured and compared to those obtained from the analytical solution and from finite element analysis (FEA). General good agreements are found between the results. Discrepancies between the computational and experimental results at low and high frequencies are also discussed. Explanations are offered in the study to disclose the mechanism causing the discrepancies. The dependency of the dynamic response of the ribbed plate on the distance between the excitation force and the rib is also investigated experimentally. It confirms the findings disclosed in a previous analytical study [T.R. Lin, J. Pan, A closed form solution for the dynamic response of finite ribbed plates, Journal of the Acoustical Society of America 119 (2006) 917-925] that the vibration response of a clamped ribbed plate due to a point force excitation is controlled by the plate stiffness when the source is more than a quarter plate bending wavelength away from the rib and from the plate boundary. The response is largely affected by the rib stiffness when the source location is less than a quarter bending wavelength away from the rib. © 2011 Elsevier Ltd. All rights reserved. Source


McKee K.K.,Curtin University Australia | McKee K.K.,Cooperative Research Center for Infrastructure and Engineering Asset Management | Forbes G.L.,Curtin University Australia | Mazhar I.,Curtin University Australia | And 2 more authors.
Advances in Applied Mechanics Research, Conference Proceedings - 7th Australasian Congress on Applied Mechanics, ACAM 2012 | Year: 2012

The ISO standard 10816 gives acceptance levels of vibration for centrifugal pumps in the form of a severity Chart. The measured 10-1000 Hz RMS velocity vibration of pumps within a given size and physical setup can be judged against the severity chart limits to give an indication of the pumps running health. This single RMS velocity value, although having being shown to be a reasonably robust measurement tool for analysing the condition of a centrifugal pump, does not allow discrimination between failure types resulting in the increased vibration, and indeed overlooks the subtleties of the pump condition state. This limitation in the use of general RMS velocity vibration levels for use with rotating machinery health is well documented, and a vast number of more sophisticated techniques, to pin point faults in specific machinery, have been developed. These techniques, although powerful, often require detailed information, such as the number of balls in a specific bearing within the machine. This information is often not readily available for a given pump setup. Tailoring these sophisticated vibration diagnostic tools for a specific pump setup can require a considerable amount of man hours and expertise, therefore having general vibration diagnostic tools which dont require extensive data about the particular pump setup would be ideal. It is proposed in this paper that the use of Octave band spectral measurements of pump vibration can strike a better balance between the two extremes of vibration analysis being: (i) overall RMS vibration velocity levels, (ii) highly specific analysis techniques such as envelope analysis for bearing fault detection. The use of Octave band spectral measurements still allows broad employment in centrifugal pump setups without a high degree of specific setup details being required. Within this paper modification of the ISO-10816 severity charts for use with Octave frequency band measurements is presented. With the use of some in-field vibration measurements, initial justification and validation of the modified vibration severity levels is presented. Source


Wiewiora A.,Southern Cross University of Australia | Wiewiora A.,Cooperative Research Center for Infrastructure and Engineering Asset Management | Trigunarsyah B.,Queensland University of Technology | Murphy G.,Cooperative Research Center for Infrastructure and Engineering Asset Management | And 2 more authors.
International Journal of Project Management | Year: 2013

A considerable amount of research has confirmed the relationship between organizational culture and knowledge sharing behaviours. However, less research has been conducted on the impact of project sub-cultures in relation to the sharing of knowledge between projects, particularly in project based organizations (PBOs). The unique structures and contexts characterized by PBOs indicate the need to investigate further the impact of cultures present within PBOs and their effect on knowledge sharing. We report on a rich case study of four large Australian-based PBOs whereby the cultural values of these large organizations were seen to impact significantly on whether project teams were more or less likely to improve inter-project knowledge sharing. Furthermore, this research demonstrates the utility of using Cameron and Quinn's (2005) Competing Values Framework to evaluate culture in the context of PBOs. © 2013 Elsevier Ltd and PMA. Source


Siddhpura A.,University of Western Australia | Siddhpura A.,Cooperative Research Center for Infrastructure and Engineering Asset Management | Paurobally R.,University of Western Australia | Paurobally R.,Cooperative Research Center for Infrastructure and Engineering Asset Management
International Journal of Advanced Manufacturing Technology | Year: 2013

Flank wear is the most commonly observed and unavoidable phenomenon in metal cutting which is also a major source of economic loss resulting due to material loss and machine down time. A wide variety of monitoring techniques have been developed for the online detection of flank wear. In order to provide a broad view of flank wear monitoring techniques and their implementation in tool condition monitoring system (TCMS), this paper reviews three key features of a TCMS, namely (1) signal acquisition, (2) signal processing and feature extraction, and (3) artificial intelligence techniques for decision making. © 2012 Springer-Verlag London Limited. Source


Siddhpura M.,University of Western Australia | Siddhpura M.,Cooperative Research Center for Infrastructure and Engineering Asset Management | Paurobally R.,University of Western Australia | Paurobally R.,Cooperative Research Center for Infrastructure and Engineering Asset Management
International Journal of Machine Tools and Manufacture | Year: 2012

Chatter vibrations are present in almost all cutting operations and they are major obstacles in achieving desired productivity. Regenerative chatter is the most detrimental to any process as it creates excessive vibration between the tool and the workpiece, resulting in a poor surface finish, high-pitch noise and accelerated tool wear which in turn reduces machine tool life, reliability and safety of the machining operation. There are various techniques proposed by several researchers to predict and detect chatter where the objective is to avoid chatter occurrence in the cutting process in order to obtain better surface finish of the product, higher productivity and tool life. In this paper, some of the chatter stability prediction, chatter detection and chatter control techniques for the turning process are reviewed to summarize the status of current research in this field. The objective of this review work is to compare different chatter stability prediction, chatter detection and chatter control techniques to find out most suitable technique/s and to identify a research scope in this area. One scope of research has been identified as establishing a theoretical relationship between chatter vibration and tool wear in order to predict tool wear and tool life in the presence of chatter vibration. © 2012 Elsevier Ltd. All rights reserved. Source

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