Additive manufacturing of composites with tailored fibre architectures in fastened joint applications

Abstract

This thesis investigates the enhancement of mechanical properties in carbon fibre reinforced polymer (CFRP) composites, with a specific focus on the bearing performance of fastened joints, by tailoring the fibre architectures using 3D printed continuous carbon fibre (CF) filaments. The research methodology integrates fibre steering techniques with finite element analysis (FEA) to improve the design and functionality of CFRP composites in fastened joint applications. It aims to explore the potential of tailored fibre architectures in reinforcing the mechanical robustness of these materials. A comprehensive methodology is employed combining computational modelling with rigorous experimental validation. A novel multi-scale finite element modelling approach is developed, wherein continuous CF filaments are used as the fundamental modelling units, allowing for a detailed analysis of fibre path effects on laminate performance. The experimental outcomes, evaluating the bearing response of fastened joints under double-shear tensile loading, indicate significant enhancements in bearing strength and energy absorption through precise fibre steering and path design. The research also extends to the application of these methodologies in repairing deformed composite laminates, presenting the practical utility and environmental benefits of the developed techniques. The conclusions of this study emphasise the revolutionary potential of integrating 3D printing with computational modelling in the field of composite materials. The developed methodologies not only provide insights into the mechanical behaviour of composites but also facilitate the development of novel approaches in material design and repair. This work significantly contributes to the advancement of composite material science, particularly in the context of mechanically fastened joints, offering a foundation for future innovations and applications in the industry.