Pseudo-ductile composites with micro-wrapped hybrid tows

Abstract

A novel method of hybridisation of dry fibres with different failure strains was developed using a micro-wrapping process to introduce pseudo-ductile behaviour in high-performance composites. Three different hybrid configurations (T700-carbon/S-glass, M55-carbon/S-glass and M55-carbon/T700-carbon) were prepared using the micro-wrapping process with low strain to failure fibre component at the core of the hybrid structure. To investigate pseudo-ductile behaviour, different unidirectional (UD) and UD woven composites were manufactured using micro-wrapped and equivalent side-by-side hybrid tows. Tensile test results revealed that all micro-wrapped hybrid composites demonstrated excellent pseudo-ductile behaviour. In contrast, side-by-side hybrid composites exhibited a significant stress drop after low-strain fibre failure. In the stress-strain graph, micro-wrapped hybrid composite showed a plateau region after pseudo-yielding, followed by a second linear region with increasing stress and strain before final failure. Overall, micro-wrapped core-shell hybrid with low and high-strain carbon fibre showed significant pseudo-ductility with potential for a low-cost manufacturing method.