An asymmetric elastic metamaterial model for elastic wave cloaking

Abstract

Elastic material with its elastic tensor losing minor symmetry is considered impossible without introducing artificially body torque. Here we demonstrate the feasibility of such material by introducing rotational resonance, the amplified rotational inertia of the microstructure during dynamical loading breaks naturally the shear stress symmetry, without resorting to external body torque or any other active means. This concept is illustrated through a realistic mass-spring model together with analytical homogenization technique and band structure analysis. It is also proven that this metamaterial model can be deliberately tuned to meet the material requirement defined by transformation method for full control of elastic wave, and the relation bridging the microstructure and the desired wave functionality is explicitly given. Application of this asymmetric metamaterial to design elastic wave cloak is demonstrated and validated by numerical simulation. The study paves the way for material design used to construct the transformation media for controlling elastic wave and related devices.

arXiv comment22 pages, 8 figures

References in corpus (7)

• Achieving control of in-plane elastic waves
• Chiral effect in plane isotropic micropolar elasticity and its application to chiral lattices
• Negative effective mass below a cut-off frequency
• Hyperelastic cloaking theory: Transformation elasticity with pre-stressed solids
• Exterior cloaking with active sources in two dimensional acoustics
• Complete characterization and synthesis of the response function of elastodynamic networks
• Realizable response matrices of multiterminal electrical, acoustic, and elastodynamic networks at a given frequency

Cited by in corpus (10)

• Metamaterial shields for inner protection and outer tuning through a relaxed micromorphic approach
• Cloaking strategy for Love waves
• Cloaking in-plane elastic waves with swiss rolls
• A unifying perspective on linear continuum equations prevalent in science. Part II: Canonical forms for time-harmonic equations
• Static and dynamic analysis of auxetic three-dimensional curved metamaterials in both axial and circumferential directions
• Scattering-coded elastic meta-boundary
• Discrete Transformation Elasticity: An Approach to Design Lattice-based Polar Metamaterials
• Topological defect states in elastic phononic plates
• Extremal micropolar materials for elastic wave cloaking
• Classification of rotational zero modes in 2D micropolar solids