The Effect of the Distance From the Center of a Weld to the Fixed End on the Residual Stress and Stress Intensity Factor of a Piping Weld

The fixed conditions of butt welds between straight pipe and valve or pump in the actual piping system are different from those of straight pipes. However, the effect of fixed condition on the residual stress and the stress intensity factor for evaluation of structural integrity of cracked piping is not clear. In this study, the finite element analyses were conducted by considering the differences in the distance from the center of weld to the fixed end L to clarify the effect of fixed condition on the residual stress and the stress intensity factor. For the 600A piping, the residual stress distribution was not affected by the distance L. Furthermore, the stress intensity factor of circumferential crack under the residual stress field could be estimated by using the existing simplified solution for piping.