Tunable flexural wave band gaps in a prestressed elastic beam with periodic smart resonators

This paper theoretically studies the propagation of flexural waves in an actively controllable locally resonant (LR) beam. It is shown that the band gaps can be simultaneously tuned by the axial force and the active electrical control actions. In some special cases, a super-wide pseudo-gap resulted from the combination of the resonance and Bragg gaps can be observed. The condition of inducing such pseudo-gap is further obtained with a closed-form expression with respect to the electrical control parameter and the axial force, which can be explored to actively control the broadband pseudo-gap by tuning these two parameters.