Results and analysis
Delamination during the drilling of a carbon-epoxy composite

Figure 7 shows an experiment/numerical calculation comparison of the thrust forces F_z for a 4 mm thick EH25-T2H carbon/epoxy plate and a quasi-isotropic stacking sequence [90°/+45°/0°/ – 45°]_2s. While the loading imposed on the drill core represents 50% of the total loading, the relative difference between the results given by the numerical model and those given by experiment is significant (of the order of 50%) as soon as the number of plies under the drill is greater than 2.