Fatigue damage evolution in thick composite laminates: Combination of X-ray tomography, acoustic emission and digital image correlation

摘要

The main purpose of this study is to provide a thorough experimental investigation of fatigue damage mechanisms and evolution in thick carbon/epoxy laminate subjected to bending load. The use of X-ray computed tomography (CT) in this study has allowed the visualization of all damage present in the studied laminates, which made it possible to identify, quantify and locate them precisely and therefore, to identify the physical origin of residual strength decrease and acoustic emissions (AE). Furthermore, the results of the AE analysis have provided very valuable information about the nature and evolution of damage. However, the determination of the depth and size of internal damage was not possible with this technique. The displacement field measured by digital image correlation (DIC) made it possible to determine and monitor the strain field evolution during the experiments. The combination of the results of the three non-destructive techniques used in this work has allowed better characterization of fatigue damage evolution in the studied laminates, and provide a complete and accurate description of the different mechanisms involved during their damage process.