Measuring strain energy release rate (GIc) in novel fibre shape composites

The poor through-thickness properties of continuous fibre reinforced plastics are a major concern for their wider use. A new approach, based upon fibres of novel cross-section, is currently being evaluated. Correct selection of the fibre shape could allow extensive load transfer by mechanical interlocking of the fibres and matrix as well as by interfacial bonding over a larger surface area. Shaped and circular fibre composites were prepared and Mode I Double Cantilever Beam (DCB) testing of 0°/0°, 0°/45° and 0°/90° interfaces was undertaken. The Mode I DCB testing indicated that shaped fibres can provide >50% improvement in strain energy release rate (GIc) over circular fibres.