• Allegri, Giuliano
• Trask, Rs
• Quino, Gustavo
• Wisnom, Michael R.
• Pickard, Laura Rhian

Abstract

Inspired by natural composites such as bamboo (Figure 1) or bone, the NextCOMP programme seeks to improve compressive performance through a novel, hierarchical approach to advanced composites. Features designed to improve compressive performance are introduced at multiple length scales. Novel fibres and resins are under development, along with new approaches at the ply level.<br/><br/>This new approach to composites brings its own manufacturing challenges, combining multiple methods both automated and manual.<br/><br/>Cylindrical struts, consisting of carbon-fibre epoxy pultruded rods of circular cross section plus an infused resin, have previously been manufactured [2] and subjected to compression after impact testing [3]. Struts overwound with Kevlar to confine the kink bands exhibited greater compressive strength than comparable struts without overwinding. X-ray CT images (Figure 2) show multiple smaller kink bands in the former case compared to a single large kink band in the latter.<br/><br/>In the hierarchical approach overbraiding of individual rods is employed, introducing hybridisation where rod and overbraid fibres differ. Various materials and geometries are under test (Figure 3), including a range of rod cross section shapes and areas. These overbraided rods are then integrated into larger structures, including but not limited to cylindrical struts.<br/><br/>This presentation focuses on our latest investigations into the design, manufacture and compression testing of single and hierarchical composite overbraided architectures. Optimisation of overbraiding for different test cases will be explored. The work is placed in context regarding what this new approach to composites may mean for manufacturing, with a look towards future challenges and opportunities.

Topics

• impedance spectroscopy
• Carbon
• strength
• composite
• resin