Delamination damage analysis of GNPs-Filled carbon fiber composites through three-point bending and drilling experiments

This study performed a three-point bending test and drilling process at different feed rotation speeds on 18-layer carbon fibre composite materials filled with 0.5 wt% GNPs and unfilled layered carbon fibre composites. The three-point bending test determined the composite materials’ bending strength. The effect of GNPs additive on carbon fiber composite materials was examined according to the delamination damages in the holes after the drilling process performed at different parameters. Numerical values of delamination damages were obtained by applying the image processing method to the microscope images obtained from the hole surfaces of the composite materials. It was determined that delamination damages occurred less in carbon fibre composites filled with 0.5 wt% GNPs compared to neat carbon fibre composite materials. As a result of the drilling process, it was observed that delamination damages increased with increasing speed and feed speeds in both composite samples. The least delamination damage was obtained at 150 mm/min feed speed and 1000 rpm speed. GNPs additive slowed down the formation of delamination damage by increasing the interlayer strength in carbon fiber composite materials. It also effectively preserved the composite structure’s structural integrity by distributing the load between the layers in a balanced manner.