A study on the measurement of a path-dependent J-integral due to a weld residual stress field

The J-integral is an important fracture mechanics parameter applicable for many areas which provide the integrity evaluation methods. Fracture of welding structure usually starts at weld region due to high weld residual stress and defects easily found in it. However, it is difficult to calculate the correct J-integral of the structure containing weld because J-integral is path dependent due to the residual stress. It is also true that there are no evidence that the J-integral measuring methods suggested by the ASTM or others are appropriate for J-integral specimens with the residual stress. Therefore, in this paper, the J-integral measuring methods suggested by the ASTM or others were evaluated and the CMOD based J-integral measuring method is suggested as an appropriate method for measuring J-integral of specimens containing weld residual stress