A NEW LIMIT-LOAD FORMULA FOR THE LIGAMENT OF A SURFACE CRACK IN LEAK-BEFORE-BREAK (LBB) ASSESSMENT

During leak-before-break (LBB) assessment, it is of great importance t o predict the limit-load of the ligament at a surface crack. The curre nt limit-load formulae tend to be overconservative, so by using them i n LBB assessment, the actual transient length of the through crack at its penetration will be underestimated, thus giving unsafe assessment results. This is not acceptable in engineering practice. In this paper a new ligament collapse model of a surface crack is proposed. The der ivation of a relevant new limit-load formula for a ligament is present ed. Finally, the authors' formula is compared with other formulae in d etail via numerous graphs.