Chapter 8 - Damage Mechanisms - Including Edge Effects - in Carbon Fibre-reinforced Composite Materials

Abstract

Abstract Polymer matrix based composite materials offer substantial improvements over metals for structural application. Their light weight, high strength and high stiffness make them candidate materials for primary components especially in the aerospace industry, where they are replacing metallic materials, components and structures. Their characteristic response to a tensile or compressive loading, however, is substantially different from that of metals. Whereas in metals, damage development under static loading exhibits only one primary failure mode, which is the initiation and propagation of one single crack (which can be described with simple fracture-mechanics tools), composite materials exhibit a combination of different failure modes. There are the initiation and multiplication (and not propagation) of cracks, including transverse, longitudinal and angle-ply cracking in the matrix along fibres (intraply cracks), delaminations (interply cracks), fibre fracture and fibre/matrix interface debonding. This chapter reviews the static material properties and the damage development, which is accompanied by different damage mechanisms, for various types of carbon fibre-reinforced plastic laminates. Special attention will be given to continuous fibre-reinforced composites. In addition, some basic damage mechanisms in composites reinforced with aligned short fibres and with a satin woven fabric will be given.