In-Plane and Oblique Edge-on Impact on Thick Glass-Fibre/Epoxy Composite Laminates

Thick composite laminates are often required in marine applications to resist high hydrodynamic forces. In this work, damage in thick glass-fibre/epoxy laminates caused by low velocity impacts was investigated experimentally and numerically. Cubic specimens 50 x 50 x 50 mm were manufactured, and the ply stacking directions were orientated at 0 degrees, 22.5 degrees and 45 degrees to the impact plane. The impact damage was localised in the vicinity of the impactor contact area and included an interplay of fibre crushing, matrix cracks, matrix plasticity, and delaminations. Finite element modelling predicted the impact response and the type of damages. The model also quantified the primary energy absorption mechanisms which were by fibre crushing, matrix plasticity and propagation of delamination cracks. The highest impact damage resistance was obtained with the 0 degrees (in-plane) specimen due to the fibres being aligned to the impact loading direction.