Analyzing the use of carbon materials in matrices used in structural repair

In this thesis, the influence of graphene oxide (GO) incorporation into the matrix on the mechanical performance of wet lay-up repair techniques applied to carbon fiber reinforced polymer (CFRP) composite structures was investigated. The study aims to enhance the strength of wet lay-up repairs with GO reinforcement, making performance comparable to prepreg repairs. For this purpose, synthesized GO was added to the hand lay-up resin at concentrations of 0.3%, 0.5%, and 2.5%, and repair processes were carried out accordingly. The tensile strength of the GO-modified samples was then compared with those of unmodified hand lay-up and prepreg-repaired specimens. The results showed that the unmodified hand lay-up repair exhibited an average tensile strength of 282 MPa, while the prepreg repair reached 391 MPa. The sample containing 0.3% GO demonstrated a 26% lower performance compared to prepreg repair, showing clear improvement. However, the inclusion of 2.5% GO led to significant agglomeration within the matrix, resulting in a 56% reduction in strength. The most remarkable finding was observed in the sample containing 0.5% GO, which exhibited only a 0.8% reduction in tensile strength compared to the prepreg repair, effectively approaching its performance level. These findings suggest that optimized GO reinforcement can enhance the mechanical efficiency of hand lay-up repairs. For field use, GO must be pre-mixed into the resin, since on-site dispersion may compromise integrity. This study offers a promising approach for improving the reliability and cost-effectiveness of CFRP structural repairs in aerospace and aviation applications.