Compressive failure of laminates containing an embedded wrinkle: experimental and numerical study

An experimental and numerical study has been carried out to understand and predict the compressive failure performance of quasi-isotropic carbon-epoxy laminates with out-of-plane wrinkle defects. Test coupons with artificially induced fibre-wrinkling of varied severity were manufactured and tested. The wrinkles were seen to significantly reduce the pristine compressive strength of the laminates. High-speed video of the gauge section was taken during the test, which showed extensive damage localisation in the wrinkle region. 3D finite element (FE) simulations were carried out in Abaqus/Explicit with continuum damage and cohesive zone models incorporated to predict failure. The FE analyses captured the locations of damage and failure stress levels very well for a range of different wrinkle configurations. At lower wrinkle severities, the analyses predicted a failure mode of compressive fibre-failure, which changed to delamination at higher wrinkle angles. This was confirmed by the tests.