Metamaterials are microachitectured materials that exhibit unusual properties, such as negative apparent stiffness and density, not ordinarily observed. These exceptional properties allow realization of structural behavior that is not possible with conventional 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 against hazards such as blast, impact and earthquakes. Additional areas of direct transformative impact of this research are vibration control of mechanical systems, energy harvesting and sensing. The PI will hold annual workshops for high school students and teachers to introduce them to the concept of simulation-based engineering.
The 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). Within this research, an efficient and accurate multiscale computational homogenization methodology for transient dynamic response of heterogeneous materials with material nonlinearity will be developed, and a comprehensive study on wave propagation and energy dissipation characteristics of viscoelastic metacomposites will be performed. Asymptotic analysis and the mathematical homogenization techniques will be used to formulate high order balance equations that can accurately capture nonlinear dispersion. Computational solution algorithms will be developed to accurately capture the emergence of bandgaps in multidimensional microstructures. These computational tools and algorithms will be employed to tailor the morphological makeup of a composite material for achieving superior wave mitigation property at targeted frequency ranges. The focus of the investigations is on core-shell particle-reinforced composites with dissipative,viscoelastic, constituents.
