Micro-macro understanding of delamination crack initiating and growth at ply drops in thick laminates

Abstract

In the present study, scanning electron microscopy (SEM) is used to identify the relevant fractographic features on the fracture surface of specimens having experienced static and fatigue crack growth. The fracture features associated with the different opening modes, the typical fracture behaviours in static and fatigue crack growth, and the fracture behaviours close to the crack tip and remote from the crack tip are the key considerations in this study. The results and experimental methods of the study are valuable in providing insights into the dominant fracture mode, delamination damage initiation and propagation site in glass fiber-reinforced epoxy composites. The approach used in the thesis can serve as guidelines as to how to approach and undertake a failure analysis.