Vibration attenuation behaviors of finite sandwich plates with periodic core

Abstract A periodic sandwich plate is obtained by gluing homogeneous aluminum plates onto two sides of a 1-d periodic plate consisted of epoxy and silicone rubber. Analysis of transmission loss indicates that band gaps still exist in this new structure. The research on effects of layer thickness and core component ratio on band-gap properties is followed. It turns out that lower-frequency band gaps can be better ensured with thicker core layer and higher component ratio of soft core. Moreover, attenuation behaviors of periodic sandwich plates under various boundary conditions are studied experimentally and analytically. To look into the impact mechanism of boundary conditions, a set of linear and torsional springs connected to ends of the periodic sandwich plate are employed to model specific boundary conditions by adjusting the springs’ stiffness. In this way, a detailed change pattern of attenuation ranges when periodic sandwich plates are under different boundary conditions is revealed. It shows that as torsional and linear stiffness increase, attenuation ranges tend to move toward higher frequency, and attenuation behaviors of the periodic sandwich plate will gradually approach that of the same structure under clamped boundary condition given both torsional and linear stiffness tend to infinity. Finally, a special boundary condition in which the periodic sandwich plate is coupled with cylinder shell is discussed as well, with the focus on attenuation behaviors of the periodic sandwich plate and vibration responses of the cylinder outer surface.