Effect of adhesive thickness on stress intensity factor for edge interface crack in adhesively- bonded joint

Abstract

This paper deals with the effect of adhesion layer on the stress intensity factor for small edge interface crack in bonded plates under uniaxial tension or bending. In this study, the stress intensity factors of the small edge interface crack are analyzed by the crack tip stress method with varying the crack length, adhesive thickness and material combination. The stress intensity factor of the edge interface crack is controlled by the singular stress field at the interface free edge in adhesively-bonded joint without the crack when the crack is very small. The calculation shows that the normalized stress intensity factors of the small edge interface crack under uniaxial tension or bending are related to the ratio between the crack length and the adhesive thickness (a/h) and the singularity index λ at the interface edge without the crack. Then, it is found that the normalized stress intensity factors can be expressed as F_1,2=C_1,2(h/a)^1-λ and the parameters C₁ and C₂ are constant values when a/h<10^-3.