  In this paper, we extend the recently proposed extended scaled boundary
finite element method (xSBFEM)~\cite{natarajansong2013} to study fracture
parameters of interfacial cracks and cracks terminating at the interface. The
approach is also applied to crack growth along the interface and crack
deflecting into the material within the context of linear elastic fracture
mechanics. Apart from the stress intensity factors, the T-stress can be
computed directly from the definitions, without any requirement of path
independent integrals. The method aims at improving the capability of the
extended finite element method in treating crack tip singularities of cracks at
interfaces. An optimum size of the scaled boundary region is presented for
multimaterial junctions. The proposed method: (1) does not require special
numerical integration technique; (2) does not require a priori knowledge of the
asymptotic fields and (3) the stiffness of the region containing the crack tip
is computed directly. The robustness of the proposed approach is demonstrated
with a few examples in the context of linear elastic fracture mechanics. A
discussion on the crack growth along the interface and crack deflecting into
the material is also presented.
