ISSN: 1945-7553
CODEN: JTEVAB
Page Count: 4

Microcracks: The Hazard Function and Reliability Inspection

Lawson, L
Center for Quality Engineering and Failure Inspection and Northwestern University, Evanston, IL

Chen, EY
Northwestern University, Evanston, IL

(Received 26 August 1994; accepted 13 February 1995)

Abstract

Reliability inspections of structures for fatigue cracks are traditionally conducted at equispaced intervals because, it is assumed, the average slope of the hazard function following an inspection does not change from one inspection to the next. This study examines the common case where fatigue cracks nucleate continually over time. In such cases it is found that the slope of the hazard function after inspection may tend to increase from one inspection to the next, suggesting that inspection intervals should decrease with increasing service life. A formalism is introduced that allows calculation of the hazard function from microcrack data.

Keywords:
microcracks, crack density, initiation, hazard function, reliability inspection

Paper ID: JTE10432J
DOI: 10.1520/JTE10432J
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