The evolution characterization and mechanism analysis of interface damage of carbon fiber composites under transverse compression were studied by μCT technique

Abstract The damage mechanism and damage characterization of Unidirectional (UD) filament‐wound composites caused by transverse compression are few and imperfect at present. Therefore, the prepared carbon fiber composites were subjected to transverse compression loading until crushed. The μCT technique was used to scan the different compression load steps, and then the 3‐Dimensional (3D) model was reconstructed. The pore quantization and porosity analysis of the reconstructed 3D model were carried out to observe the change of cracks with the increase of load. The fracture morphology and fracture location were observed by Scanning Electron Microscope (SEM). Finally, the digital volume correlation (DVC) method is used to study the three‐dimensional strain field of the loaded specimens. The results show that the carbon fiber composite has higher initial porosity and a faster damage evolution rate. The initial porosity is 1.35%, and the porosity increases 2.9 times from the initial stage to the imminent fracture stage, reaching 3.91%. Finally, DVC technology is used to obtain the three‐dimensional strain field of the sample and analyze the local strain around the damage initiation. Highlights The theory of transverse compression mechanics of carbon fiber composites is analyzed. To explore the damage evolution law and mechanism of carbon fiber composites. The focus of DVC analysis is strain localization near damage initiation.