A Numerical Study of 3D Kelvin Cell Arrangements as a Basis for Locally Resonant Acoustic Metamaterials

Locally resonant acoustic metamaterials (LRM) are designed to inhibit wave propagation in targeted frequency bands, evoked by the resonant behavior of sub-structural elements attached to a host structure. Typically, the resonant attachments are periodically clustered on the host structure and scaled smaller than the wavelength of interest. A novel approach in designing LRM comprises 3D cellular structures. Such architectures exhibit diverse resonances that are tunable by modifying the geometry and could thus provide structurally inherent multi-resonators without requiring embedded resonant units. This contribution investigates these prospects of 3D cellular architectures in a parametric study using the finite element method. An isometric Kelvin cell (KC) is employed as a reference design strategy. The reference’s material properties and geometry are altered and the structural dynamic behaviors of the respective designs are examined. It is demonstrated that rigid body rotations of the cell’s square faces modify the coupling between longitudinal and transverse displacement directions and induce various mode shapes that are potentially exploitable to attain efficient low-frequent vibration attenuation. It is discussed whether the KC-resonator strategy provides an opportunity for achieving LRM with tunable broadband features, followed by an outline of future research steps employing this concept.     «

Locally resonant acoustic metamaterials (LRM) are designed to inhibit wave propagation in targeted frequency bands, evoked by the resonant behavior of sub-structural elements attached to a host structure. Typically, the resonant attachments are periodically clustered on the host structure and scaled smaller than the wavelength of interest. A novel approach in designing LRM comprises 3D cellular structures. Such architectures exhibit diverse resonances that are tunable by modifying the geometry a...     »