Investigation of Bandgap Structure in Coupled Acoustic- Mechanical System

In this research, we study the applicability of a generic methodology for reducing the interaction and resulting vibration problems in coupled acoustic-mechanical systems based on bandgap structures. Finite element analysis with acoustic-structure interaction (ASI) is used to study the dynamic and acoustic behavior of a representative non-planar plate unit cell and the Bloch-Floquet theory is used to apply the results to an infinite material. Several numerical experiments are provided to gain physical insight into how bandgaps in the acoustic and mechanical domains can be created and located at desired frequency ranges and with specific geometrical dimensions. In addition, the bandgap properties are analyzed in view of the possibility for the control of mechanical waves in the presence of strong ASI. The coupled bandgap phenomenon is investigated based on the result of a vibro-acoustic analysis for an acoustic cavity with a corresponding periodic structure made from the non-planar unit cell. Particular attention is given to the effect on both vibrational/acoustic properties of the finite structure. An experiment investigation of a 3D printed finite structure is explored to study the bandgap phenomenon and vibro-acoustic transmission.