Boundary element analysis of stress state at the bridged zone of an interface crack

The direct boundary element method has been applied to analyze stresses in a fracture process zone (a crack bridged zone) and to calculate the modulus of stress intensity factors for structures with bridged interface cracks under mechanical loading. The bridged zones of interface cracks are considered as parts of these cracks and it is assumed that distributed spring-like bonds with given bond deformation law link crack surfaces. Numerical analysis of the bridged interface cracks is based on the multi-domain formulation of the boundary integral equation method. The results are compared with those obtained previously for a straight crack at the interface between two different materials using singular integral-differential equations. Parametric analysis of the influence of the bridged zone bond stiffness, the physical-mechanical properties of jointed materials and the bridged zone length on the stress intensity factor modulus is performed. In addition, the problem for a curvilinear bridged crack at the interface between a matrix and a cylindrical inclusion in a composite material is considered.