X-ray computed tomography study of compressive failure in a notched unidirectional glass fiber-reinforced composites

An experimental study on the axial compressive failure of a notched unidirectional (UD) glass fiber-reinforced composites has been performed to better understand the failure mechanisms in three dimensions (3D). A sequence of failure initiation and propagation has been monitored based on X-ray computed tomography (CT) images of the sample during failure. The CT images have shown that fiber kinking failure is the main failure mechanism, and there are two different types of kink bands, classified as type 1 and type 2 by final geometric form. The type 1 kink band, which has an X shape, extends outward from the notch along the width direction before finally creating a shear type 2 kink band at a distance from the notch. The novelty of this work involves observing the nucleation and propagation of fiber kink bands in three-dimensional space, as well as defining and quantifying kink band variables.