Repeated Low‐Velocity Impact Response of Graphene Nanoplatelet‐Reinforced Basalt Fiber Composites

ABSTRACT This study examines the effect of graphene nanoplatelets (GPLs) on the repeated low‐velocity impact behavior of basalt fiber–reinforced epoxy composites (BFRCs). Multiscale composites containing 0.2 wt.% and 0.4 wt.% GPL were fabricated and tested under repeated impact loading up to 40 cycles. Key parameters including peak force, contact stiffness, bending stiffness, and absorbed energy were analyzed to evaluate impact resistance under progressive damage. SEM fractography was conducted to investigate failure mechanisms and GPL dispersion. Results show that GPL incorporation significantly modifies the impact response of BFRCs. All laminates exhibited increased peak force and contact stiffness between the 10th and 20th impacts, indicating a temporary strengthening effect. At this stage, the 0.2 wt.% GPL composite achieved a 44% increase in peak force compared to pure BFRC, while the 0.4 wt.% GPL composite showed limited improvement. Beyond 20 impacts, stiffness degradation occurred due to damage accumulation; however, GPL‐modified composites exhibited delayed degradation. At higher impact numbers, the 0.4 wt.% GPL composite demonstrated superior bending stiffness retention and energy absorption. SEM analysis confirmed crack deflection, platelet pull‐out, and enhanced interfacial bonding, contributing to improved damage tolerance.