A fracture analysis of welded pipes with consideration of residual stresses

摘要

With consideration of residual stresses, a fracture parameter J{sub}(ld) is examined for a welded pipe containing a circumferential crack. The fracture parameter is computed from the energy difference of two cracked solids with slightly different crack sizes by a combined finite element and finite difference method. Our computational results show that, when the residual stresses are not considered, the values of J{sub}(ld) for different contours are path independent for the cracked pipe subject to remote axial stresses. Our computational results also show that the values of J{sub}(ld) with consideration of residual stresses are lower than those without consideration of residual stresses for the cracked pipe subject to large remote axial stresses.The trends of the local crack tip opening angles (CTOAs) with and without consideration of residual stresses are very similar to those of the J{sub}(ld)'s with and without consideration of residual stresses.