Composites of extreme anisotropy Initial experiments

Anisotropy is inherent in composite materials, and dependent on the type and orientation of the reinforcement. For unidirectional carbon fibre composites, the ratio of tensile modulus to shear modulus is Very high, in the order of 30: 1. For the majority of applications of composites this level of anisotropy is excessive, and additional fibre directions are used to achieve the necessary suite of properties. There are, however, some potential applications of composites in which greater levels of anisotropy are required, and for these the term 'composites of extreme anisotropy' has been coined. This paper briefly discusses one potential application, reviews the options for the production of composites of extreme anisotropy, and describes work carried out on their development at Bristol University.