COST-EFFECTIVE HIGH-PERFORMANCE COMPOSITES

A hybrid composite material based on mixtures of ultra-high performance carbon fibres in the principal stress directions and cheaper standard fibres in the secondary stress directions has been developed. A wide range of mechanical properties have been measured on this material and, for comparison, also on the base materials. The hybrid material has been shown to have a mechanical performance similar to that of the ultra-high performance carbon fibre base material tested, a performance generally much improved over that of the standard fibre composite. This has been achieved together with a significant cost saving through the use of lower cost standard fibres in secondary, lower stressed layers. At present price levels, ultra-high performance fibres are typically 2 1/2 times the cost of standard carbon fibres, although prepregs show just a 40% difference in cost. The philosophy of mixing standard and ultra-high performance carbon fibres, as described in this work, could lead to cost reductions of about 17% based on prepreg costs, but if alternative fabrication methods were used the savings could be much greater.