Evaluation of Hybrid Composite Materials.

An examination of the available fiber prepregs clearly suggests that the higher stiffness and strength materials such as boron and graphite have higher price levels than the lower stiffness and strength prepregs such as Kevlar-49 and S-Glass. A logical outcome of this observation is to combine the two categories of fibers into hybrids so that the price levels can be brought down, perhaps at the expense of some strength and stiffness properties. The goal of such hybridization is to make composite materials more competitive with metals such as aluminum and titanium. In this report, a methodology is presented to obtain minimum cost and weight configurations for simple structural configurations which are representative of real world structures, over a practical range of loadings. Weight differences are incorporated into the cost comparisons through the use of a premium cost to quantify the value of weight savings. Material costs, manufacturing costs and premiums are all treated as variables in this design study.