In‐situ micro‐CT damage evolution of C/GFRP under tensile loading at 80 and 150°C using threshold analysis and DVC technology

Abstract Carbon/glass hybrid laminates, that is, carbon/glass fiber‐reinforced plastics (C/GFRPs) are widely applied in engineering because of their low cost; however, the damage evolution mechanism of C/GFRPs at high temperatures remains unclear. In this study, the in‐situ computed tomography (CT) non‐destructive testing technology was applied during tensile tests, with four load states on the C/GFRP at 80 and 150°C. Image reconstruction was performed on ten thousand slices to obtain a three‐dimensional (3D) model. Threshold analysis was performed to obtain quantitative data on the pores in the C/GFRP and to explore the evolution pattern of porosity at high temperatures. Using the digital volume correlation (DVC), the fracture position of the specimen was predicted in the 3D strain field. Using scanning electron microscopy (SEM), the failure modes of the epoxy resin and fibers in the microstructure were investigated. Their study showed that small pores have a higher sensitivity to loads. The pore increment at 150°C was higher than that at 80°C, along with a higher damage evolution rate. This study helps to understand the distribution of porosity and the damage evolution mechanism of C/GFRP laminates at high temperatures from 3D space and temporal evolution. Highlights Developing a heating device integrated on a CT in‐situ tensile platform. Image reconstruction and threshold analysis on slices of C/GFRPs under 80–150°C. Exploring the damage mechanism of resin and fibers under high temperature. 3D strain field and fracture prediction based on DVC technology.