Source of Support : National Science Foundation, CMMI Mechanics of Materials Program.

Program Manager Dr/ Thomas Siegmund.

Abstract:
Metamaterials are man-made materials that exhibit unusual properties (such as negative apparent stiffness and density) not ordinarily observed in nature. These exceptional properties allow realization of structural behavior that is not possible with natural materials. One such possibility is suppressing or significantly damping the propagation of waves of certain of frequencies within a structure. This project investigates the possibility of realizing metacomposite materials that can suppress or significantly damp vibration, impact and blast loads by tuning the material microstructure and properties of its components. If realized, the innovation of this novel and unusual class of materials will result in very effective
protection systems for civil infrastructure (e.g., gas and oil pipelines, buildings, bridges and others) against man-made and natural hazards such as blast, impact and earthquakes. Additional
areas of direct transformative impact of this research are vibration control of mechanical
systems (aeroacoustic loading in air vehicles, sound proofing, etc.), energy harvesting and
sensing, and others.
The proposed research will elucidate the fundamental relationships between time-dependent viscoelastic properties of the constituents of acoustic metacomposite materials, its microstructural morphology and its wave mitigation characteristics under dynamic loading. This fundamental structure-property relationship is currently lacking for metamaterials that do not exhibit elastic response. The primary hypothesis of this project is that the interacting mechanisms of wave dispersion induced by the material heterogeneity and wave dissipation due to material viscosity can be employed to control and suppress wave propagation within large frequency bands (i.e., tunable bandgaps).