Wave propagations of a periodic sandwich beam by FEM and the transfer matrix method

Periodic structures can act as filters for wave propagation within certain bands of frequency called stop bands. The partially constrained layer damping (CLD) treatments are placed periodically along the beam and covered with a constrained layer to control the longitudinal wave propagation in this beam. The CLD placed on the beams act as the sources of impedance mismatch with viscoelastic characteristics. The location and width of the stop bands can be changed with different configurations of the periodic structure. The finite element model and the transfer matrix method are developed to study the one-dimensional, periodically structural problems to predict the performance of the system. The behavior of the periodic structure are evaluated at different length ratios and base beam materials. The investigation in the present study provides the basic guidelines to design periodic structures with smart materials to achieve desired filtering characteristics.