The effect of graphene nanoparticles on the strength of sandwich panel structure under quasi-static loading and low-velocity impact

In recent decades, the use of nanoparticles in composite structures and composite sandwich panels has expanded due to the achievement of mechanical and physical properties. In the present study, the effect of graphene nanoparticles on the strength of a sandwich panel structure with a new vein geometry model under quasi-static loading and low-velocity impact has been investigated. The vein structures are made of glass/epoxy layers with different percentages of 0.0, 0.1, 0.3 and 0.5% of graphene nanoparticles. In addition, polyurethane foam was used in the center of the sandwich vein structure. In order to check the damage inside the vein structure, cut-out images of the damage have been prepared and the results have been reported. In addition, FE-SEM analysis was used to investigate the microstructure and evaluate the distribution of graphene nanoparticles in the polymer structure. The characteristics of crashworthiness in the tested samples were discussed. It was concluded that this type of sandwich vein structure with polyurethane foam core can limit the propagation of the damage in quasi-static loading and drop weight test and keep the sandwich structure healthy. On the other hand, as a result of the impact, several different failure modes have occurred, including fiber failure, matrix cracking, delamination, Foam detachment, foam failure, and foam crushing. After the FE-SEM analysis, it was observed that the sandwich structure with 0.3% of nanoparticles has a higher density than the other tested structures