Ultimate axial load capacity of a delaminated beam-plate

The paper presents elastic buckling and postbuckling analysis of an axially loaded beam-plate with an across-the-width delamination symmetrically located at an arbitrary depth. It is found that, for a relatively short and thick delamination, the buckling load of the delaminated plate is a close lower bound of the ultimate axial load capacity. In the case of a relatively slender delamination, the postbuckling axial load can be considerably greater than the buckling load, while the failure of the plate may or may not be governed by delamination growth. The energy-release rate associated with delamination growth is systematically computed for various combinations of the delamination length and axial load. The resulting curves determine the possibility and the stability characteristics of delamination growth and provide a basis for finding the ultimate axial load capacity. Nomenclature = half-length of delamination = thickness of delamination = half-length of the plate = thickness of the plate =a/t = a/h = axial forces = bending moments w = transverse deflections = bending stiffnesses Young's modulus in the axial direction amplitude of deflection a h / t a a Pi Mf u, v,