Quasi-Metamaterials: Quasicrystalline Mechnical Metamaterial Concepts for Advanced Engineering Application

EPSRC Research Portfolio areas: Continuum mechanics (grow), Structural Mechanics (maintain)

Description:
A microstructured quasicrystalline material is created combining basic unit cells with a lack of perfect periodicity. Quasicrystalline assemblies are a particular case or more general quasiperiodic ones. Recent research carried out by the team in Cardiff on one-dimensional quasicrystalline-based materials has shown that those structures display peculiar properties related to elastic wave propagation. In particular, the dynamic spectra of such waveguides (which reveal the capability of the structure to transmit waves at a given frequency) possess scaling and self-similarity features that can be exploited to design innovative metamaterials able to shield incoming elastic waves and mitigate unwanted vibrations. These features can be described with an elegant mathematical theory that is based on the existence of an invariant function called Kohmoto's invariant.
The project will focus on the extension of the above preliminary findings to a fully two- and three-dimensional framework in order to provide guidelines for an effective design of innovative metamaterials based on a quasicrystalline (QC) microstructure. In particular, the following milestones will be pursued: i) identification of the invariants that oversee the dynamical properties of two- and three-D QC materials (1st year); ii) investigation of dispersion diagrams of QC materials and their scaling and self-similarity properties as an extension of what is known in one-dimensional structures (2nd year); iii) study of prototype devices to assess elastic wave attenuation at different frequencies (3rd year); iv) identification of design guidelines for the use of artificial QC-based metamaterials for engineering applications both in seismic and MEMS engineering (final six months).