Structural composite materials tailored for damping

This paper reviews the tailoring of structural composite materials for damping. By the use of the interfaces and viscoelasticity provided by appropriate components in a composite material, the damping capacity can be increased with negligible decrease, if any, of the stiffness. In the case of cement-matrix composites, the use of silica fume as an admixture results in increases in both the damping capacity and the storage modulus. In the case of continuous fiber polymer-matrix lightweight composites, the use of submicron-diameter discontinuous carbon filaments as an interlaminar additive is more effective than the use of an interlaminar viscoelastic layer in enhancing the loss modulus when the temperature exceeds 50 °C. Surface treatment of the composite components is important. In the case of steel reinforced concrete, the steel reinforcing bar (rebar) contributes much to the damping, but appropriate surface treatment of the rebar further enhances the damping.