861 research outputs found
Theoretical foundation of some criteria of equilibrium stability of plates
Equilibrium stability of orthotropic rectangular plate
Parabolic Metamaterials and Dirac Bridges
A new class of multi-scale structures, referred to as `parabolic
metamaterials' is introduced and studied in this paper. For an elastic
two-dimensional triangular lattice, we identify dynamic regimes, which
corresponds to so-called `Dirac Bridges' on the dispersion surfaces. Such
regimes lead to a highly localised and focussed unidirectional beam when the
lattice is excited. We also show that the flexural rigidities of elastic
ligaments are essential in establishing the `parabolic metamaterial' regimes.Comment: 14 pages, 4 figure
Active cloaking of finite defects for flexural waves in elastic plates
We present a new method to create an active cloak for a rigid inclusion in a
thin plate, and analyse flexural waves within such a plate governed by the
Kirchhoff plate equation. We consider scattering of both a plane wave and a
cylindrical wave by a single clamped inclusion of circular shape. In order to
cloak the inclusion, we place control sources at small distances from the
scatterer and choose their intensities to eliminate propagating orders of the
scattered wave, thus reconstructing the respective incident wave. We then vary
the number and position of the control sources to obtain the most effective
configuration for cloaking the circular inclusion. Finally, we successfully
cloak an arbitrarily shaped scatterer in a thin plate by deriving a
semi-analytical, asymptotic algorithm.Comment: 19 pages, 14 figures, 1 tabl
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