Damping of Vibration Using Periodically Voided Viscoelastic Metamaterials

This thesis investigates the damping effects of a metamaterial, on structural vibration, by inducing periodic voids in the base damping material as opposed to infusing the damping material with other material. Metamaterials have been used previously to improve the damping of vibrational waves and acoustic waves through wave scattering and wave reflection at periodic impedance changes. Impedance changes can occur at both material boundaries and geometric changes of the medium. Impedance changes cause wave scattering, wave reflection, and changing of wave speed. The low frequency region of the vibration spectrum is generally harder to dampen due to the longer wavelengths. By slowing the waves down, the wavelength can be shortened and the viscoelastic material will be more effective at damping the waves. The metamaterial in the thesis has one, two, three, and four periodically located voids in the viscoelastic damping material to determine the effectiveness of the damping compared to the same beam with no damping material applied and the beam covered completely with the standard viscoelastic damping material. This research will include both finite element models of the beam and concept testing to explore the damping effects of the metamaterial.