Failure characterisation of CF/epoxy V-shape components using digital image correlation and acoustic emission analyses

Abstract Testing of V-Shape demonstrator components formed from carbon fibre epoxy composites was undertaken to assess the failure mechanisms at the corner section (V-Shape) of a square beam structure under static and fatigue loading configurations. Digital image correlation and acoustic emission analyses were used to determine the time to failure, as well as the location of failure, providing additional insights for failure characterisation. Digital image correlation was used on the surface of the specimens’ side as it analysed the displacements and strains on the externally visible through-thickness region. Acoustic emission analyses identified the origin and location of stress waves generated within the sample which were related to damage events. These techniques have shown a higher sensitivity to determining the onset of damage and the time to failure, in comparison to load drops, crosshead displacement changes, and strain gauge measurements, providing a more conservative and accurate measurement of component failure. They have also proven successful at determining the location of failure initiation, highlighting the added benefits of incorporating these techniques into component analyses.