Effect of Shape of Bonded Dissimilar Materials on Stress Intensity Factor of Small Edge Interface Crack
Seiji IOKA, Takashi MATSUDA and Shiro KUBO
Abstract:Free-edge stress singularity develops near the intersection of the interface and the free-surface of bonded dissimilar materials. Therefore, fracture of bonded dissimilar materials may occur at the intersection of the interface and the free-surface. Free-edge stress singularity depends on the combination of material properties and shape of bonded dissimilar materials. In this study, the relation between the stress intensity factor of a small edge crack on interface and free edge stress singularity of bonded dissimilar materials under external loading was investigated numerically by using the boundary element method with changing the combination of wedge angle of bonded materials. 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 of small edge crack on interface K1, K2 were proportional to the intensity of free-edge stress singularity without crack KƒÐ. The numerically determined proportional coefficient between K1 and KƒÐ agreed well with the theoretical one, and was not affected by crack length when proper normalization was applied. Key Words:Bonded dissimilar materials, Interface edge crack, Stress intensity factor, Free-edge stress singularity, Principle of superposition