Vibrations of three layered damped sandwich plate composites

Theoretical and experimental results are presented and discussed for the transverse driving point mechanical impedances, as well as for the transfer impedances, of damped composite plates made up of a thin viscoelastic layer sandwiched between two elastic layers. Analytical results are determined by finite element approximations. Due to the elements used and the system to be modeled, several fundamental assumptions or restrictions usually adopted in analytical investigations are removed. The dependence on frequency and temperature of the dynamic properties of the viscoelastic materials is taken into consideration. A companion experiment was conducted, for comparison purposes, on such damped composite plates suspended in air by lightweight elastic shock cords and driven at the center by an electromechanical vibration shaker. Good correlations between the test data and analytical solutions are obtained over a wide frequency range for two configurations.