Unlocking the potential of graphene films embedded within 3D woven glass fiber reinforced composites for enhanced damage protection

This study employs a novel co-curing approach to fabricate 3D glass fiber reinforced polymer (GFRP) composites with enhanced damage tolerance by incorporating graphene nanoplatelet (GNP) surfacing films. Low-velocity impact (LVI) tests were conducted on four different samples: pristine GFRP and GFRP composites with 1 wt%, 2 wt%, and 5 wt% GNP surfacing films co-cured with the laminate during resin infusion. The impact tests were performed at energy levels of 20 J, 30 J, and 50 J using a 6.20 mm diameter impactor. Moreover, a flexure-after-impact (FAI) test was also performed to assess the effects of impact-induced damage on the residual strength of LVI samples. The LVI and FAI results demonstrated that 2 wt % GNP-GFRP composites exhibited slightly better damage performance compared to the pristine GFRP composite. This improvement in LVI and post-FAI performance is attributed to the toughening effect of the 2 wt % GNP surfacing film and the enhanced interfacial adhesion between the co-cured GNP film and the 3D GFRP composite. Additionally, short beam shear testing was conducted to evaluate the interlaminar shear strength (ILSS) of the films with the composites. Notably, the ILSS of the 2 wt% GNP-GFRP composite improved by 10 % compared to the pristine GFRP composite. These findings suggest that incorporating GNP surfacing films is a promising strategy for damage-resistant structures in aerospace applications.