The objective of this paper is to evaluate the crack stability of a nuclear
main steam pipe, considering load reduction effect due to the presence of
circumferential through-wall crack. Also, optimization techniques are adopt
ed to simulate the crack effect on the elbow component of piping systems. B
y using a general beam element that contains a discontinuous cross-section,
piping analysis is performed to obtain the reduced load. Considering this
reduced load, LBB design concept is applicable to the nuclear main steam pi
pe system. Also, by combining an optimization program and a general finite
element analysis software, the appropriate dimensions are simplified and an
equivalent beam element representing the effect of crack in the elbow coul
d be successfully obtained. (C) 2001 Elsevier Science B.V. All rights reser
ved.