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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
20140006569
Document Type
Conference Paper
Authors
Koshti, Ajay M.
(NASA Johnson Space Center Houston, TX, United States)
Date Acquired
June 3, 2014
Publication Date
March 9, 2014
Subject Category
Statistics And Probability
Quality Assurance And Reliability
Report/Patent Number
JSC-CN-30391
Meeting Information
SPIE Smart Structures/NDE 2014(San Diego, CA)
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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