Abstract
Polymer composites have generated increased interest in the development of damped structural materials because of their low density, and excellent stiffness and damping characteristics. The objectives of this paper are to study the improvement and optimization of damping in fiber reinforced structural composite materials at the micromechanical level by coating some of the fibers with special polymers which have high damping. Since shear deformation is essential for viscoelastic damping in polymers, and large shear strains are generated near the fiber/matrix interface in composites, the use of special viscoelastic polymer fiber coatings is an effective way to improve damping in such composites. Of particular interest are hybrid composites having a mixture of coated and uncoated fibers, since coating all the fibers would cause unacceptable reductions in other important properties like strength and stiffness.