On the transition from shear-driven fibre compressive failure to fibre kinking in notched CFRP laminates under longitudinal compression

This paper investigates longitudinal compressive failure in notched unidirectional and cross-ply carbon/epoxy specimens. Dedicated test jigs were developed to observe the failure processes at the microscale. In situ and post-mortem fractography reveals two types of failure mechanisms: (i) shear-driven fibre compressive failure and (ii) kink-band formation. The sequence of events leading to failure and the reasons for shear-driven fibre compressive failure or kink-band formation are investigated and discussed. Those findings are discussed further in a separate paper (Gutkin et al., accepted for publication) [1] where an FE micromechanical model is used to investigate numerically the failure mechanisms found in longitudinal compression.