THE CURVED INTERFACIAL CRACK BETWEEN DISSIMILAR ISOTROPIC SOLIDS

The paper examines analytically the role of curvature on the stress di stribution of a curved interfacial crack between dissimilar isotropic solids. The crack-tip fields under in-plane and antiplane shear loadin g are studied, respectively. Using an asymptotic expansion of the circ ular interface geometry, the asymptotic solutions of the stress and di splacement fields in the vicinity of the curved crack tip derived from modified stress functions is obtained. The eigenfunctions associated with the eigenvalues lambda for the curved crack consist of not only r (2) terms, but also r(lambda+1), r(lambda+2),... terms. In some cases, the terms r(lambda+')(ln r), r(lambda+2)(ln r), etc. may also exist. Two examples, frictionless contact near the circular crack-tip under i n-plane loading and circular interfacial crack subject to antiplane sh ear loading, are derived in a closed-form asymptotic solution to eluci date the curvature effect. The case of fully open interfacial crack is also briefly described. Comparing the eigenfunction solutions of stra ight interfaces, the curvature effect enters the stress fields from th e third-order term of the asymptotic solution for both cases. The cond ition for the existence of the, r(1/2)(ln r) term in the circular inte rfacial crack with frictionless contact is presented explicitly. Copyr ight (C) 1997 Elsevier Science Ltd.