ANALYSIS OF CRACK CLOSURE IN UNIDIRECTIONAL COMPOSITE PLATES SUBJECT TO BENDING LOADS

Finite element analyses were performed to investigate the effect of crack closure in unidirectional fibrous composite plates with through-wall-thickness cracks and subjected to bending loads. The analyses showed that, for a composite plate, crack closure at the compression side of a through-wall-thickness crack increased the crack opening displacement and bending stress around the crack tip at the tensile surface of the plate. This was due to the effect of transverse shear. Thus, not considering crack closure in a composite plate subject to a bending load will result in a not only inaccurate but also non-conservative solution for a through-wall-thickness crack.