COST-EFFECTIVE HIGH-PERFORMANCE COMPOSITES

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