Evaluation of the flexural properties and failure evolution of a hybrid composite manufactured by automated dry fibre placement followed by liquid resin infusion

The market for composites is developing rapidly due to the widespread general requirement for lightweight design in various industries. However, the proliferation of fibre-reinforced composites is limited partly due to the lack of ductility associated with these materials. Hybridisation of fibres has emerged as an important strategy to increase the ductility of polymer composite materials. In the present work, water based dispersion was used to develop a dry fibre carbon tape and a hybrid glass/carbon tape which are both compatible with automated deposition techniques. Dry fibre preforms were manufactured using laser-assisted dry fibre placement (DFP) and laminates were subsequently manufactured using vacuum assisted liquid resin infusion. The hybrid composite exhibited both higher flexural strength (8%) and higher strain-to-failure (58%) relative to the carbon based laminate. To understand the failure modes, X-ray micro-computed tomography was used in conjunction with interrupted flexural tests to monitor the evolution of damage. The progressive failure analysis revealed that for hybrid composites, damage propagation was delayed due to the staggered arrangement of glass and carbon fibres. The majority of damage in the hybrid composite was located in the carbon fibres tows.