A numerical investigation into size effects in centre-notched quasi-isotropic carbon/epoxy laminates

Numerical modelling of scaled centre-notched [45/90/−45/0]4s carbon/epoxy laminates was carried out. The in-plane dimensions of the models were scaled up by a factor of up to 16. A Finite Element (FE) method using the explicit code LS-Dyna was applied to study the progressive damage development at the notch tips. Cohesive interface elements were used to simulate splits within plies and delaminations between plies. A failure criterion based on Weibull statistics was used to account for fibre failure. There is a good correlation between the numerical and experimental results, and the scaling trend can be explained in terms of the growth of the notch tip damage zone. The modelling gives new insights into the damage development in the quasi-isotropic laminates with sharp cracks, specifically, the growth of splits, delaminations and local fibre breakage.