A Numerical and Theoretical Study on Relationship between Stress Intensity Factor of a Small Edge Crack on Interface and Free-Edge Stress Singularity of Bonded Dissimilar Materials

摘要

Free-edge stress singularity develops near the intersection of the interface and the free-surface of bonded dissimilar materials. Fracture at bonded dissimilar materials may therefore occur from an interface crack near the intersection of interface and free-surface. In this study, the relationship between the stress intensity factor of a small edge crack on interface of bonded dissimilar materials and free-edge stress singularity under external loading was investigated numerically by using the boundary element method. The relationship was also investigated theoretically by using the principle of superposition. The results of numerical analyses were compared with those of theoretical analyses. It was found that stress intensity factors K_1, K_2 were proportional to the intensity of free-edge stress singularity K_(sigma). The numerically determined proportional coefficient between K_1 and K_(sigma) agreed well with the theoretical one, and was not affected by crack length.