Abstract This study presents a comprehensive investigation into the synergistic influence of fiber stacking sequence and graphene nanoplatelets (GnPs) content on the mechanical and low-velocity impact performance of Kevlar/Carbon hybrid epoxy composites. Two symmetric stacking sequences C5K10C5 (carbon skins) and K5C10K5 (Kevlar skins) were fabricated with 0, 1, 2, and 3 wt% GnPs using a vacuum-assisted resin transfer molding (VARTM) process. Quasi-static tensile and three-point bending tests were conducted to evaluate in-plane and out-of-plane mechanical properties, while low-velocity impact tests were performed to assess damage tolerance. The results reveal that fiber architecture is the dominant factor for stiffness and strength: the C5K10C5 configuration exhibited superior tensile and flexural strength, while the K5C10K5 configuration demonstrated exceptional impact damage tolerance, characterized by large deformation and complete impactor rebound. The influence of GnPs was highly content-dependent: 1 wt% GnPs significantly enhanced tensile and flexural strength by improving fiber–matrix adhesion, whereas higher GnPs contents (2–3 wt%) promoted progressive damage mechanisms, maximizing total absorbed energy under impact at the expense of reduced strength due to agglomeration. This work provides novel insights into the multi-scale design of hybrid composites, highlighting how stacking sequence and nanofiller content can be strategically tailored to meet specific structural or protective application requirements.
Erkliğ et al. (2026) studied this question.