Kinked crack at a bi-material ceramic interface – Numerical determination of fracture parameters

In the fabrication process of ceramic composite materials or in service interface cracks could appear in one of the constituents. This work reports the stress intensity factors solution of a kinked crack whose corner is on the interface of two bonded dissimilar ceramic materials subjected to tension parallel to the interface and to tension normal to the interface. The finite element method was used to calculate the stress intensity factors at the tips of the crack. The effects of the material properties of the ceramic composite constituents, the kinked crack length, the interface crack length, and the kinked angle were investigated. A convergence study was carried out in order to find the proper distance r for collecting the displacement data for the crack flank displacement method. Results for the modulus of the complex stress intensity factors for the bi-material combinations with the homogeneous case, based on Suo and Hutchinson approach show consistent agreement for a range of interface crack lengths, kinked crack lengths and kinked angles.