Structural Deformations on Critical Cracked Pressurised Pipe Bends: Implication on the Von Mises Stresses

This paper presents an analytical study on the modification in Von Mises stresses determined across the bends of throughwall critically cracked pipe bends subjected to internal pressure due to the presence of shape irregularities. Two critically cracked 90 degree pipe bend models having pipe ratios of 5 and 10, each with bend ratios of 2 and 3 were considered for the 3D finite element analysis. Analyses taking into account elastic-perfectly-plastic materials with the small geometry change option was conducted. The finite element results indicates the variation in stress in the inner surface of intrados, extrados, crown and crack tip regions due to influence of bend radius and also due to ovality and thinning underscoring the necessity for inclusion of shape deformations in the analysis of cracked pipe bends. (C) 2017 Elsevier Ltd. All rights reserved.