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Vibration Based Crack Detection in a Rotating DiskThis paper describes the experimental results concerning the detection of a crack in a rotating disk. The goal was to utilize blade tip clearance and shaft vibration measurements to monitor changes in the system's center of mass and/or blade deformation behaviors. The concept of the approach is based on the fact that the development of a disk crack results in a distorted strain field within the component. As a result, a minute deformation in the disk's geometry as well as a change in the system's center of mass occurs. Here, a notch was used to simulate an actual crack. The vibration based experimental results failed to identify the existence of a notch when utilizing the approach described above, even with a rather large, circumferential notch (l.2 in.) located approximately mid-span on the disk (disk radius = 4.63 in. with notch at r = 2.12 in.). This was somewhat expected, since the finite element based results in Part 1 of this study predicted changes in blade tip clearance as well as center of mass shifts due to a notch to be less than 0.001 in. Therefore, the small changes incurred by the notch could not be differentiated from the mechanical and electrical noise of the rotor system. Although the crack detection technique of interest failed to identify the existence ofthe notch, the vibration data produced and captured here will be utilized in upcoming studies that will focus on different data mining techniques concerning damage detection in a disk.
Document ID
Acquisition Source
Glenn Research Center
Document Type
Technical Memorandum (TM)
Gyekenyesi, Andrew L.
(Ohio Aerospace Inst. Brook Park, OH, United States)
Sawicki, Jerzy T.
(Cleveland State Univ. Cleveland, OH, United States)
Martin, Richard E.
(Cleveland State Univ. Cleveland, OH, United States)
Haase, Wayne C.
(Aerogage Corp. Sterling, MA, United States)
Baaklini, George
(NASA Glenn Research Center Cleveland, OH, United States)
Date Acquired
August 27, 2013
Publication Date
September 1, 2005
Subject Category
Aircraft Design, Testing And Performance
Report/Patent Number
Funding Number(s)
WBS: WBS 22-728-30-06
Distribution Limits
Public Use Permitted.
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