Failure of 3D-printed composite continuous carbon fibre hexagonal frames

This study presents an approach to enhancing and expanding the structural performance of composite materials by tailoring their geometry. We explored the potential of continuous carbon fibre composite additive printing to create complaint frames based on hexagonal cell design with the aim to better understand and control their mechanical performance. Our investigation examines the failure behaviour of these frames under remote tensile loading. By experimenting with various geometries and aspect ratios at the frame sites, we gained insight into different failure loads and modes. To predict these results, we developed a computational model based on multiscale homogenisation and the Hashin damage criterion, which showed a high degree of precision compared to our experimental results. The findings validate the effectiveness of our computational model, but also highlight the practical applications of additive manufacturing of composites. This research aims to contribute to the advancement of structural design and material optimisation by engineering of composite materials for specific applications, emphasising the integration of their intrinsic strength and lightweight properties with material efficiency and compliance achieved through geometric design considerations.