Optimizing the damage tolerance of carbon-fibre composites using hollow fibre layers

Initial results are presented on the damage tolerance optimisation of carbon fibre composites using hollow fibre layers. Several hybrids were tested each comprising hollow glass fibre surface layers applied to carbon fibre laminated substrates. Impact testing revealed significant crushing of the hollow surface fibres before damage initiated in the carbon substrate. Low residual performance drop off resulted, despite the presence of high levels of surface damage. Significant potential for improving the hybrid construction is noted, however when compared to conventional laminates, current unoptimised systems still demonstrated up to 59% improvement in residual compressive performance, per unit mass, at 1mm dent depth.