MODE I AND MODE II STRESS INTENSITY FACTORS FOR A SLANTED-EDGE-CRACK AFFECTED BY AN ADJACENT HORIZONTAL CRACK UNDER REMOTE TENSION

Fracture mechanics has been used in Fitness-for-Service assessments of structures containing cracks. The stress intensity factors (SIFs) at the crack tip are the key information in assessing the remaining service life of a cracked component. Extensive studies have been carried out on the mutual influence of adjacent parallel cracks. However, to date no solutions are available for non-parallel cracks. In the present analysis mode I (KI) and Mode II (KII) SIFs of a slanted-edge-crack affected by an adjacent non-parallel horizontal crack are obtained. KI and KII are evaluated for a wide range of the slanted edge crack angle β =0^◦ to 75^◦, for various normalized horizontal (S/a2 = -0.4 to 2) and vertical (H/a2 = 0.4) separation distances and for several crack lengths. The problem is solved using a 2-D, plane strain, finite element model, which was successfully validated against presently available solutions. It is found that the presence of the embedded crack always amplifies KI of the edge crack while KII might be either amplified or attenuated depending on the crack configuration. Furthermore, the present results indicate that, for the purpose of Fitness-for-Service, the effective SIF at the tip of the slanted crack always increases due to the presence of the embedded crack.