ارزيابي انتگرال J سه بعدي در حوزه هاي تنش پسامد جوشكاري

Cracks in Residual Stress Evaluation of 3D J-Integral for Fields Caused by Welding

The J-integral has widespread usage in fracture mechanics problems. In cases where residual stresses exist in the component, the standard J-Integral would not be path-independent. In order to make it path-independent, the original form of the integral should be modified. In this paper, the J-integral is studied for the pre-existing cracks in a cylinder with residual stresses caused by girth-welding. For this purpose, semi-elliptical cracks are considered in various longitudinal and circumferential positions on the inner and outer surfaces of the cylinder. For these cracks, the modified J-integral is evaluated under pure residual stress and various combinations of residual stresses and pressure loadings. It is observed that in all cases the modified integral remains path-independent.