Leak-before-breakbehaviorofstaticallyindeterminatepipingsystemOriginalResearchArticle

Structuralintegrityconsideringthefatiguehavebecometobeimportant,asenergy-relatedstructuressuchasnuclearpipingsystemsespeciallyhavebeenusuallyoperatingundercyclicloads.Thisstudyisconcernedabouttheleak-before-break(LBB)behaviorwhenpipeincludingacircumferentialcrackissubjectedtoacyclicload.AttentionswerepaidtotheproposalofassessmentmodelsandconditionsontheLBBbehaviorconsideringacrackshapeatwallpenetrationunderacyclicload,thecomparisonofLBBconditionbetweenastaticloadandacyclicload,andthecharacteristicofthefatigueLBBbehaviorunderstaticallyindeterminatesystem.ItisconcludedthatLBBbehaviorismorelikelytobeoccurredinstaticallyindeterminatepipingsystem,asthereductionofultimatestrengthduetoasufficientredistributionofbendingmomentinthissystemwasrelativelysmall.ThisbenefitonstructuralintegrityofstaticallyindeterminatesystemwasappliedtothefatigueLBBbehaviorenvisionedthevalidityandthesuperiorityofthefatigueLBBbehaviorinstaticallyindeterminatepipingsystem.