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Modeling the X-Ray Process, and X-Ray Flaw Size Parameter for POD StudiesNondestructive evaluation (NDE) method reliability can be determined by a statistical flaw detection study called probability of detection (POD) study. In many instances the NDE flaw detectability is given as a flaw size such as crack length. The flaw is either a crack or behaving like a crack in terms of affecting the structural integrity of the material. An alternate approach is to use a more complex flaw size parameter. The X-ray flaw size parameter, given here, takes into account many setup and geometric factors. The flaw size parameter relates to X-ray image contrast and is intended to have a monotonic correlation with the POD. Some factors such as set-up parameters including X-ray energy, exposure, detector sensitivity, and material type that are not accounted for in the flaw size parameter may be accounted for in the technique calibration and controlled to meet certain quality requirements. The proposed flaw size parameter and the computer application described here give an alternate approach to conduct the POD studies. Results of the POD study can be applied to reliably detect small flaws through better assessment of effect of interaction between various geometric parameters on the flaw detectability. Moreover, a contrast simulation algorithm for a simple part-source-detector geometry using calibration data is also provided for the POD estimation.
Document ID
Acquisition Source
Johnson Space Center
Document Type
Conference Paper
Khoshti, Ajay
(NASA Johnson Space Center Houston, TX, United States)
Date Acquired
April 17, 2014
Publication Date
March 9, 2014
Subject Category
Instrumentation And Photography
Structural Mechanics
Report/Patent Number
Meeting Information
Meeting: SPIE Smart Structures/NDE 2014
Location: San Diego, CA
Country: United States
Start Date: March 9, 2014
End Date: March 13, 2014
Sponsors: International Society for Optical Engineering
Distribution Limits
Work of the US Gov. Public Use Permitted.
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