Shear-wave manipulation by embedded soft devices

TL;DR

This paper develops a theoretical framework for shear-wave manipulation using embedded hyperelastic devices, demonstrating how different deformations affect wave transmission and reflection, and proposing novel soft-matter wave control devices.

Contribution

It provides a systematic analysis of wave behavior at interfaces of pre-deformed hyperelastic materials and introduces new embedded devices for shear-wave control.

Findings

Total transmission occurs under constrained uniaxial tension and simple shear.

Wave reflection occurs under ordinary uniaxial tension and hydrostatic compression.

Proposed devices include a unidirectional cloak, a splicable beam bend, and a concave lens.

Abstract

Hyperelastic transformation theory has proven shear-wave manipulation devices with various functions can be designed by utilizing neo-Hookean material with appropriate pre-deformation. However, it is still elusive that how can such devices match with the background medium in which they embedded. In this work, we present a systematic formulation of the transmission and reflection of elastic waves at the interface between un-deformed and pre-deformed hyperelastic materials. With the combination of theoretical analyses and numerical simulations, we specifically investigate the shear-wave propagation from an un-deformed neo-Hookean material to the one subject to different homogeneous deformations. Among three typical deformation modes, we found "constrained" uniaxial tension and simple shear guarantee total transmission, whereas "ordinary" uniaxial tension and hydrostatic compression cause wave reflection. On this basis, three embedded shear-wave manipulation devices, including a unidirectional cloak, a splicable beam bend, and a concave lens, are proposed and verified through numerical simulations. This work may pave the way for the design and realization of soft-matter-based wave control devices. Potential applications can be anticipated in nondestructive testing, structure impact protection, biomedical imaging, and soft robotics.