In-situ X-ray computed tomography of composites subjected to fatigue loading

In-situ X-ray computed tomography and online stiffness monitoring were used to study damage initiation and propagation in multi-directional carbon fiber reinforced composite coupon subjected to tension-tension fatigue loading. It was found that a resolution of the CT system of 8 µm was sufficient to capture matrix crack inside the specimen. A clear correlation was found between the increasing number of matrix cracks and the observed stiffness degradation of the composite specimen