NEW THEORETICAL APPROACH TO THE STRENGTH OF FIBRE COMPOSITE HYBRID MATERIALS.

A fibre composite hybrid material generally consists of two or more fibre types contained in a single matrix. There are several equations already in existence which allow the calculation of the strength of the resulting composite. However, the most commonly used equations assume either a sharp transition in the failure strain of the composite when the volume ratio of the two fibre species crosses a critical value of volume ratio, or that there are distinct failure strains for each of the two fibre species. In the new theory it is assumed that the failure strain of the low elongation component can be linearly increased to the failure of high elogation component in a manner predicted by the rule-of-mixtures. The equation predicts an upper limit to strength which may show the 'hybrid effect', a synergistic strengthening of the composite properties, subject to the correct choice of constituents for the hybrid.