Additively manufactured Graphene-SMP sheets embedded with GFRP for hybrid adaptive aerospace composite structures

In this study, we investigate the structural and functional properties of additively manufactured shape memory polymer (SMP) sheets enhanced with varying weight percentages of graphene nanoplatelets (GNPs) using digital light processing (DLP). By embedding through “co-injecting and co-curing” the manufactured sheets within glass fiber reinforcements, smart and fully adaptive hybrid aerospace composites were developed. The incorporation of 0.1 wt.% GNPs into the SMP matrix during manufacturing increased the failure strain by approximately 50% while maintaining a tensile strength comparable to that of pristine SMP. The co-curing approach ensured seamless integration of the 3D-printed SMP sheets into traditional glass fiber (GF) composites, significantly improving interfacial adhesion and overall mechanical and shape memory performance. Furthermore, a unique “in-situ hybrid printing” technique for SMP-GF composites was developed and eliminating the need for a secondary adhesive process, enhancing resin impregnation efficiency, and strengthening interfacial bonding. Comprehensive mechanical characterization, including tensile, flexural, and peel tests, revealed the multi-scale interfacial mechanisms responsible for the enhanced performance. The co-cured hybrid composites exhibited a tensile strength of 81 MPa and demonstrated good shape memory behavior, with a shape recovery ratio exceeding 80% and a shape fixity ratio of approximately 60% over five repeated testing cycles. The proposed methodology offers a promising approach for enhancing the mechanical and functional performance of hybrid GFRP composites, demonstrating significant potential for lightweight, high-strength, and adaptive structures in aerospace applications.