Stress Intensity Factors for Defects in Two Common Weld Joints

Defects are commonly in weld joints depending on the process condition and workmanship of the welding process. Under good control environment, the amount and size of the defects can be very small and do not compromise the integrity of the weld joints. In other cases, the amount and size of the defects in the weld joints can be large and, therefore, can limit the integrity of the structure. Determination of critical flaw sizes of the welds requires accurate calculation of stress intensity factors of cracks of various lengths at different locations for their use in crack growth evaluation under cyclic loading. Two commonly used welded joints, namely butt and corner weld joints, were investigated. Three crack configurations for each of the two welded joints were considered. Finite element method was used in conjunction of the M-integral to obtain the stress intensity factors for various lengths of the cracks. Results were then used to perform the fitness-for-purpose assessment of these welds under spectral loading. Methodology and results of the stress intensity factor calculation for the above-mentioned cracks are covered in this paper.