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Development of Eddy Current Technique for the Detection of Stress Corrosion Cracking in Space Shuttle Primary Reaction Control ThrustersA recent identification of stress corrosion cracking in the Space Shuttle Primary Reaction Control System (PRCS) thrusters triggered an extensive nondestructive evaluation effort to develop techniques capable of identifying such damage on installed shuttle hardware. As a part of this effort, specially designed eddy current probes inserted into the acoustic cavity were explored for the detection of such flaws and for evaluation of the remaining material between the crack tip and acoustic cavity. The technique utilizes two orthogonal eddy current probes which are scanned under stepper motor control in the acoustic cavity to identify cracks hidden with as much as 0.060 remaining wall thickness to the cavity. As crack growth rates in this area have been determined to be very slow, such an inspection provides a large safety margin for continued operation of the critical shuttle hardware. Testing has been performed on thruster components with both actual and fabricated defects. This paper will review the design and performance of the developed eddy current inspection system. Detection of flaws as a function of remaining wall thickness will be presented along with the proposed system configuration for depot level or on-vehicle inspection capabilities.
Document ID
20060052518
Acquisition Source
Johnson Space Center
Document Type
Conference Paper
Authors
Wincheski, Buzz
(NASA Langley Research Center Hampton, VA, United States)
Simpson, John
(Lockheed Martin Space Operations Hampton, VA, United States)
Koshti, Ajay
(NASA Johnson Space Center Houston, TX, United States)
Date Acquired
August 23, 2013
Publication Date
January 1, 2006
Subject Category
Structural Mechanics
Meeting Information
Meeting: Review of Progress in Quantitative NDE
Location: Portland, OR
Country: United States
Start Date: July 30, 2006
End Date: August 4, 2006
Distribution Limits
Public
Copyright
Public Use Permitted.
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