X-ray micro-computed-tomography characterization of cracks induced by thermal cycling in non-crimp 3D orthogonal woven composite materials with porosity

This paper focuses on an experimental study of the thermal cycling behavior of a carbon fiber/epoxy matrix composite material reinforced with a non-crimp 3D orthogonal woven preform (3DNCOW). The aim is to characterize the damage mechanisms - i.e. matrix cracking - induced by thermal cycling thanks to X-ray micro-computed-tomography (µCT). Qualitative and quantitative descriptions of the morphology and the evolution of cracks with thermal cycling are carried out through the analysis of µCT scans of samples at different cycle numbers. In addition, since the specimens have a certain level of porosity due to the infusion process, a complete description of this defect is carried out, and its influence on the damage mechanisms induced by thermal cycling is analyzed.