  A boundary element formulation is developed to determine the complex stress
intensity factors associated with cracks on the interface between dissimilar
materials. This represents an extension of the methodology developed previously
by the authors for determination of free-edge generalized stress intensity
factors on bi-material interfaces, which employs displacements and weighted
tractions as primary variables. However, in the present work, the
characteristic oscillating stress singularity is addressed through the
introduction of complex weighting functions for both displacements and
tractions, along with corresponding non-standard numerical quadrature formulas.
As a result, this boundary-only approach provides extremely accurate
mesh-independent solutions for a range of two-dimensional interface crack
problems. A number of computational examples are considered to assess the
performance of the method in comparison with analytical solutions and previous
work on the subject. As a final application, the method is applied to study the
scaling behavior of epoxy-metal butt joints.
