Automated nanomaterial integrated repair patch production and its implementation for carbon fiber-reinforced composites

Official URL: http://risc01.sabanciuniv.edu/record=b1817193 (Table of Contents)

Fiber reinforced composites are commonly preferred as primary and secondary structures in aerospace, energy, automotive industries due to its superior structural properties and lightweight. However, composite materials have certain limitations such as low impact resistance, delamination strength, fracture toughness and repairability. This study puts forward the applicability and the striking improvements in mechanical properties which provided by graphene in the composites. The first chapter of this thesis includes a brief literature overview for nano-reinforcement of composite materials. In the second chapter, three different nano-material integrated arrangements were investigated. These systems can be categorized as the nano-reinforcement integration on the fibers, in the matrix, and both the fibers and the matrix. Notable enhancements were achieved in flexural, tensile and fracture toughness of the graphene-integrated composite structures, and microscopy images for the fracture surfaces are provided to support these results. The third chapter presents comprehensive information on the design of the electrospraying device with multiple nozzles and its manufacturing processes. Electrospraying is a highly efficient method in nano-material coating field, which is fast, user-friendly and low-cost. The new multiple-nozzle electrospraying device is aimed to lead the nanomaterial integration for the mass production in the composite technologies research center. In the last chapter, outcomes of the previous studies on TEGO integration on composites were used for the development of composite repairs. Repairing procedures were employed as matrix and interface reinforced repair patches. Two different sanding methods were tested to find the most efficient method. Shear properties of the repair patches were remarkably improved because of the interface and matrix modification with graphene-implementation. To conclude, graphene as a reinforcer was successfully employed for the improvement in mechanical properties of healthy and repaired composite structures