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Vibration-Based Method Developed to Detect Cracks in Rotors During Acceleration Through ResonanceIn recent years, there has been an increasing interest in developing rotating machinery shaft crack-detection methodologies and online techniques. Shaft crack problems present a significant safety and loss hazard in nearly every application of modern turbomachinery. In many cases, the rotors of modern machines are rapidly accelerated from rest to operating speed, to reduce the excessive vibrations at the critical speeds. The vibration monitoring during startup or shutdown has been receiving growing attention (ref. 1), especially for machines such as aircraft engines, which are subjected to frequent starts and stops, as well as high speeds and acceleration rates. It has been recognized that the presence of angular acceleration strongly affects the rotor's maximum response to unbalance and the speed at which it occurs. Unfortunately, conventional nondestructive evaluation (NDE) methods have unacceptable limits in terms of their application for online crack detection. Some of these techniques are time consuming and inconvenient for turbomachinery service testing. Almost all of these techniques require that the vicinity of the damage be known in advance, and they can provide only local information, with no indication of the structural strength at a component or system level. In addition, the effectiveness of these experimental techniques is affected by the high measurement noise levels existing in complex turbomachine structures. Therefore, the use of vibration monitoring along with vibration analysis has been receiving increasing attention.
Document ID
20050192615
Acquisition Source
Glenn Research Center
Document Type
Other
Authors
Sawicki, Jerzy T. (Cleveland State Univ. Cleveland, OH, United States)
Baaklini, George Y. (NASA Glenn Research Center Cleveland, OH, United States)
Gyekenyesi, Andrew L.
Date Acquired
September 7, 2013
Publication Date
May 1, 2004
Publication Information
Publication: Research and Technology 2003
Subject Category
Aircraft Propulsion And Power
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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