Reliability of Defect Detection in Welded Structures
Abstract
An analysis has been made of the ability of several nondestructive inspection procedures to reliably detect surface fatigue cracks. It is shown that the ability of penetrant systems of aluminum and titanium are over 90% for cracks whose surface length is greater than 0.939mm (0.037 in.) in length and decreases for cracks less than this value. The probability of detection of these cracks, given that the crack is present has been determined at 90, 95, and 99% confidence factors. The conditional probabilities associated with an error call have also been developed. For this analysis four outcomes were defined: (1) The detection of a crack that is present; (2) The missing of a crack that is present; (3) The detection of a crack that does not exist (false call); and (4) The verification that a part does not contain a flaw. Using Bayes theorem, the conditional probabilities have been established in terms of a material quality factor, an error probability ratio and a success probability ratio. The results of two inspectors, one with a 6% error probability, and the other with a 36% error probability have been examined.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1975
- Accession Number
- ADA019660
Entities
People
- B. W. Yee
- F. M. Wells
- J. K. Malpani
- P. F. Packman
Organizations
- Vanderbilt University