X-ray computed tomography for assessing impact damage in composites

X-ray computed tomography (XCT) is one of the computer-based nondestructive techniques that allows visualization of 3D images, which are reconstructed from a series of sequential 2D X-ray radiographs, of internally heterogeneous materials, including composites. Widely used for medical diagnosis (organs, bones, teeth), XCT has been used in the past two decades to analyze complex damage mechanisms in composite materials subjected to impact loading. This chapter introduces the nature of impact damage in composites and the motivation for identifying the impact damage, working principles of XCT, including specimen preparation. Key references on the impact damage assessment using XCT, in both qualitative and quantitative manners, as well as the comparison with synchrotron CT are reviewed to aid the decision of utilization of XCT for impact damage characterization. The role of XCT in the microstructural construction of finite element models and validation is also discussed.