Dynamics of quasiperiodic and quasicrystalline elastic metamaterials

Abstract

This talk describes recent progress on quasiperiodic and quasicrystalline metamaterial research done by the group. While the vast majority of metamaterials are based on periodic designs based on a repeating unit cell, quasiperiodic and quasicrystalline metamaterials break the periodicity paradigm and open new interesting possibilities. The first category is based on modulations of the properties of inclusions of otherwise periodic lattices, such as point masses, springs, resonators, or stiffeners, that are given by a deterministic non-periodic pattern. In the second case, quasicrystalline materials are based on rotational symmetries which are forbidden in periodic materials, such as 5,7,8, and 10-fold rotational symmetries. The investigation of the dynamics of such materials reveals intriguing properties such as topological bandgaps and localized vibration modes that can be manipulated by a few key parameters, and wave directionalities enabled by higher order rotational symmetries that expand the behavior known to be possible in periodic metamaterials. The talk will summarize the progress done in the area, including a large number of numerical and experimental investigations.