Mechanisms in damping of mechanical vibration by piezoelectric ceramic-polymer composite materials

The piezoelectric ceramic (piezoceramic) component of a polymer-piezoelectric ceramic composite converts mechanical energy into electrical energy and this electrical energy is dissipated as heat in a load resistance, R_x, simulated by a shunted resistance, but provided in practice by a conductive polymer composite matrix. The composite therefore dissipates the input mechanical energy via the damping mechanism provided by piezoelectric ceramic-conductive matrix material, as well as the conventional viscoelastic damping provided by the polymer. Mathematical models have been developed to characterize the damping behaviour of the composites, and the maximum damping ratio of composites can be as high as 23%. A two degrees-of-freedom (2DOF) experimental setup was developed to test the validity of the models. The experimental results are in good agreement with the theoretical predictions.