BONDED REPAIR OF A PLATE WITH INCLINED CENTRAL CRACK UNDER BIAXIAL LOADING

This paper is to study the performance of the bonded repairs of a plate containing an inclined central through-crack under a biaxial loading. The concept is to change the load path and to bypass the defect or crack in a structure. Consequently, the stress intensity factors or the energy level near the crack tip can be reduced. Also, the maximum adhesive shear stress and patch fibre stress have to meet the design criteria such that the structure will not fail in service. In general, the stresses and stress intensities are strongly influenced by the existence of the biaxial load. The problem of how to optimize the patch fibre orientation with single- or double-sided patching has been discussed. The interactions between the biaxial load and the ply orientation on the fracture behaviour of the inclined crack are studied numerically. For better repair efficiency, the results indicate that the fibre orientation should coincide with the maximum tensile load direction in double-sided patching and be perpendicular to the crack surface in single-sided patching.