Micro-CT as a well-established technique to investigate the internal damage state of a composite laminate subjected to fatigue

摘要

Micro Computed Tomography (micro-CT) has become an established non-destructive technique for microstructure investigation of composite materials, where due to the intrinsic difficulty in defining suitable damage models, it can be proved useful as such in helping to interpret and validate them. In this study the evolution of damage on several cross-ply laminates having embedded fibre optics of different diameters was investigated over several millions of fatigue cycles. High-resolution 3D X-ray tomography has been performed at different intervals in the vicinity of the sensor and damage has been quantified by counting the overall number of matrix cracks in the scanned volume. A clear evolution of damage has been noticed in accordance with a measured stiffness degradation of the laminate. Nevertheless, the results reveal that for the given loading conditions damage is not evolving in the vicinity of the fibre optics.