Reinforcement of Metals with Advanced Filamentary Composites

This paper reviews some recent applications of the concept of reinforcing metal structures with advanced filamentary composites, and presents some results of an experimental investigation of the tensile behavior of aluminum and titanium reinforced with unidirectional boron/epoxy. Results are given for tubular and flat specimens, bonded at either room temperature or elevated temperature. The composite reinforced metals showed increased stiffness over the all-metal counterpart, as predicted by the rule of mixtures, and the results were independent of specimen geometry.

The tensile strength of the boron/epoxy reinforced metals is shown to be a function of the geometry of the test specimen and the method of bonding the composite to the metal. The ultimate strength of the tubular specimens and a flat modified dogbone specimen, both bonded at elevated temperature, and a flat coupon specimen bonded at room temperature showed good agreement with predicted values, which are well above the metal counterpart. Flat coupon specimens bonded at an elevated temperature exhibited early failures, which were as much as 40 percent below predicted values.