Crack stability evaluation of nuclear main steam pipe considering load reduction effect

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 adopted to simulate the crack effect on the elbow component of piping systems. By 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 pipe 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 could be successfully obtained.