Evaluation of bimaterial stress intensity factors using a finite element boundary element alternating method

The finite element-boundary element alternating method is extended to the analysis of a crack in a bimaterial test specimen. The crack is perpendicular to, and terminates at, the interface between two dissimilar materials. The finite element method is used to model the finite-size specimen without the crack. The displacement discontinuity method (boundary element method) is used to find the stresses in the infinite bimaterial medium due to crack surface tractions. The stress intensity factors are extracted by using a closed form solution for a semi-infinite crack in an infinite bimaterial medium opened by a pair of wedge forces. The alternating method is verified by solving several bimaterial crack problems for which solutions are known. A parametric study is performed for a specimen proposed for evaluating the fracture toughness of bimaterial interfaces.