Effect of different hybrid ratios on shape memory properties of GO ‐ CF / AF hybrid‐reinforced SMCs prepared by VIHPS

Abstract Shape memory composites are widely utilized in aerospace, medical equipment, and intelligent structures. In this paper, seven types of graphene oxide‐containing carbon fiber/aramid fiber (GO‐CF/AF) epoxy resin‐based hybrid reinforced shape memory composites (SMCs) with different hybrid ratios were prepared based on the vacuum infiltration hot pressing system (VIHPS), and these seven groups of composites exhibited favorable appearances and the microstructure was more desirable. To investigate the effect of different hybrid ratios on the shape memory properties of the composites, this study was carried out by adjusting the hybrid content of aramid fibers, and the experimental analyses were performed under single and multiple cycling conditions, respectively. The results demonstrated that the composites had the largest modulus of elasticity up to 134.8 GPa, the lowest porosity of 2.7%, the shape fixation rate of 91.59%, the shape recovery rate of 98.18%, and the shape recovery force of 8.99 N when the reinforcement was exclusively carbon fibers. When the reinforcement was solely aramid fibers, the elastic modulus of the composites was 73.58 GPa, and the porosity was the highest at 5.73%. But the shape fixation rate was as high as 98.42%, the shape recovery rate was 79.84%, and the shape recovery force was 6.56 N. In addition, the fiber fracture within the composite became more and more obvious with the increase in the number of cycles. This phenomenon led to crack expansion in subsequent cycling tests, thereby impeding the effective transfer of heat and mechanical properties, and ultimately resulting in a decrease in the shape memory properties of the composite. Highlights GO‐CF/AF prepared by VIHPS has excellent shape memory properties. The shape memory properties of the composites decreased with an increasing number of cycles. The modulus of elasticity of the fiber affects the shape recovery force of the composites.