Broadband solid cloak for underwater acoustics

Abstract

Application of transformation theory to underwater acoustics has been a challenging task because highly anisotropic density is unachievable in water. A possible strategy is to exploit anisotropic modulus rather than density, while has not been experimentally demonstrated. We present an annular underwater acoustic cloak designed from particular graded solid microstructures. The geometry tailored microstructures mimics meta-fluid with highly anisotropic modulus through substantially suppressed shear wave. Transient wave experiments are conducted with the cloak in a designed 2D underwater waveguide system and proved excellent cloaking performance for enclosed target over broadband frequency 9-15 kHz. This finding paves the way for controlling underwater acoustics using the structured anisotropic modulus meta-fluid.

12 pages, 4 figures

References in corpus (4)

• Acoustic cloaking theory
• Cymatics for the cloaking of flexural vibrations in a structured plate
• Special transformations for pentamode acoustic cloaking
• Tunable cylindrical shell as an element in acoustic metamaterial

Cited by in corpus (18)

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• Adiabatic edge-to-edge transformations in time-modulated elastic lattices and non-Hermitian shortcuts
• Design of arbitrarily shaped acoustic cloaks through PDE-constrained optimization satisfying sonic-metamaterial design requirements
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• Rayleigh surface waves of extremal elastic materials
• Longitudinal elastic wave control by pre-deforming semi-linear materials
• Underwater Acoustic Multiplexing Communication by Pentamode Metasurface
• Discrete Transformation Elasticity: An Approach to Design Lattice-based Polar Metamaterials
• Non-Closed Acoustic Cloak Enabled by Sequential-Step Linear Coordinate Transformations
• Extremal micropolar materials for elastic wave cloaking
• Topology optimization of pentamode metamaterials for underwater acoustics
• Classification of rotational zero modes in 2D micropolar solids