Micromechanical Analysis of Normal Mode Damping Properties of Polymer Blend Composite Material

Micromechanical analysis of the macroscopic damping properties of a polymer blend composite with sea-island morphology are performed by using the equivalent inclusion method combined with the Mori-Tanaka theorem. In modeling, the shape of the island particle is assumed to be a spheroid whose rotational axis is aligned along the direction of the applied stress. The macroscopic complex modulus and hence the macroscopic loss factor of the composite are expressed as the function of the damping properties of constituents and the aspect ratio of spheroidal particle under the steady-state vibration of normal component in applied stress. The values of the macroscopic loss factor obtained are compared with those caliculated by using the conventional modal strain energy method (MSE). Consequently, the present values of the macroscopic loss factor become close to those by the MSE asymptotically as the aspect ratio of the particle increases and both values differ from each other in the range of relative low aspect ratio of the particle.