Study of anomalous wave propagation and reflection in semi-infinite elastic metamaterials

Wave Motion ◽  
2015 ◽  
Vol 55 ◽  
pp. 73-83 ◽  
Author(s):  
R. Zhu ◽  
X.N. Liu ◽  
G.L. Huang
Keyword(s):  
Wave Propagation ◽  
Anomalous Wave ◽  
Elastic Metamaterials

Elastic wave propagation in metamaterial rods with periodic shunted piezo-patches

2021 ◽  
Vol 263 (2) ◽  
pp. 4303-4311
Author(s):  
Edson J.P. de Miranda ◽  
Edilson D. Nobrega ◽  
Leopoldo P.R. de Oliveira ◽  
José M.C. Dos Santos
Keyword(s):  
Wave Propagation ◽  
Elastic Wave ◽  
Wave Attenuation ◽  
Periodic Structures ◽  
Band Gaps ◽  
Low Frequencies ◽  
Periodic Arrays ◽  
Extended Plane ◽  
Elastic Metamaterials ◽  
Piezoelectric Structures

The wave propagation attenuation in low frequencies by using piezoelectric elastic metamaterials has been developed in recent years. These piezoelectric structures exhibit abnormal properties, different from those found in nature, through the artificial design of the topology or exploring the shunt circuit parameters. In this study, the wave propagation in a 1-D elastic metamaterial rod with periodic arrays of shunted piezo-patches is investigated. This piezoelectric metamaterial rod is capable of filtering the propagation of longitudinal elastic waves over a specified range of frequency, called band gaps. The complex dispersion diagrams are obtained by the extended plane wave expansion (EPWE) and wave finite element (WFE) approaches. The comparison between these methods shows good agreement. The Bragg-type and locally resonant band gaps are opened up. The shunt circuits influence significantly the propagating and the evanescent modes. The results can be used for elastic wave attenuation using piezoelectric periodic structures.

scholarly journals Non-reciprocal wave propagation in modulated elastic metamaterials

2017 ◽  
Vol 473 (2202) ◽  
pp. 20170188 ◽  
Author(s):  
H. Nassar ◽  
H. Chen ◽  
A. N. Norris ◽  
M. R. Haberman ◽  
G. L. Huang
Keyword(s):  
Wave Propagation ◽  
Elastic Wave ◽  
Effective Mass ◽  
Mass Operator ◽  
High Amplitude ◽  
Coupled Mode Theory ◽  
Coupled Mode ◽  
Transient Regimes ◽  
Elastic Metamaterials ◽  
Large Frequency

Time-reversal symmetry for elastic wave propagation breaks down in a resonant mass-in-mass lattice whose inner-stiffness is weakly modulated in space and in time in a wave-like fashion. Specifically, one-way wave transmission, conversion and amplification as well as unidirectional wave blocking are demonstrated analytically through an asymptotic analysis based on coupled mode theory and numerically thanks to a series of simulations in harmonic and transient regimes. High-amplitude modulations are then explored in the homogenization limit where a non-standard effective mass operator is recovered and shown to take negative values over unusually large frequency bands. These modulated metamaterials, which exhibit either non-reciprocal behaviours or non-standard effective mass operators, offer promise for applications in the field of elastic wave control in general and in one-way conversion/amplification in particular.

SH wave propagation in joined half-spaces composed of elastic metamaterials

2017 ◽  
Vol 122 (21) ◽  
pp. 215104 ◽  
Author(s):  
Xiaona Shi ◽  
Haisheng Shu ◽  
Haiyong Zhou ◽  
Lei Zhao ◽  
Ru Liu ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Sh Wave ◽  
Elastic Metamaterials

Laser ultrasonic anomalous wave propagation imaging method with adjacent wave subtraction: Algorithm

2012 ◽  
Vol 44 (5) ◽  
pp. 1507-1515 ◽  
Author(s):  
Jung-Ryul Lee ◽  
Chen Ciang Chia ◽  
Chan-Yik Park ◽  
Hyomi Jeong
Keyword(s):  
Wave Propagation ◽  
Imaging Method ◽  
Laser Ultrasonic ◽  
Anomalous Wave

scholarly journals Broadband Frequency and Spatial On-Demand Tailoring of Topological Wave Propagation Harnessing Piezoelectric Metamaterials

2021 ◽  
Vol 7 ◽  
Author(s):  
Patrick Dorin ◽  
K. W. Wang
Keyword(s):  
Wave Propagation ◽  
Elastic Wave ◽  
Electromechanical Coupling ◽  
Expansion Method ◽  
Guided Wave ◽  
Mode Shapes ◽  
Edge States ◽  
Frequency Bandwidth ◽  
Mode Localization ◽  
Elastic Metamaterials

Many engineering applications leverage metamaterials to achieve elastic wave control. To enhance the performance and expand the functionalities of elastic waveguides, the concepts of electronic transport in topological insulators have been applied to elastic metamaterials. Initial studies showed that topologically protected elastic wave transmission in mechanical metamaterials could be realized that is immune to backscattering and undesired localization in the presence of defects or disorder. Recent studies have developed tunable topological elastic metamaterials to maximize performance in the presence of varying external conditions, adapt to changing operating requirements, and enable new functionalities such as a programmable wave path. However, a challenge remains to achieve a tunable topological metamaterial that is comprehensively adaptable in both the frequency and spatial domains and is effective over a broad frequency bandwidth that includes a subwavelength regime. To advance the state of the art, this research presents a piezoelectric metamaterial with the capability to concurrently tailor the frequency, path, and mode shape of topological waves using resonant circuitry. In the research presented in this manuscript, the plane wave expansion method is used to detect a frequency tunable subwavelength Dirac point in the band structure of the periodic unit cell and discover an operating region over which topological wave propagation can exist. Dispersion analyses for a finite strip illuminate how circuit parameters can be utilized to adjust mode shapes corresponding to topological edge states. A further evaluation provides insight into how increased electromechanical coupling and lattice reconfiguration can be exploited to enhance the frequency range for topological wave propagation, increase achievable mode localization, and attain additional edge states. Topological guided wave propagation that is subwavelength in nature and adaptive in path, localization, and frequency is illustrated in numerical simulations of thin plate structures. Outcomes from the presented work indicate that the easily integrable and comprehensively tunable proposed metamaterial could be employed in applications requiring a multitude of functions over a broad frequency bandwidth.

Elastic wave propagation in the elastic metamaterials containing parallel multi-resonators

2019 ◽  
Vol 52 (39) ◽  
pp. 395301 ◽  
Author(s):  
Yongjun Tian ◽  
Jiu Hui Wu ◽  
Hongliang Li ◽  
Cansong Gu ◽  
Zhengrui Yang ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Elastic Wave ◽  
Elastic Wave Propagation ◽  
Elastic Metamaterials

scholarly journals Broadband, reconfigurable and multifunctional elastic wave control with smart metamaterials

2017 ◽  
Author(s):  
◽  
Yangyang Chen
Keyword(s):  
Wave Propagation ◽  
Elastic Wave ◽  
Real Time ◽  
Smart Materials ◽  
Extreme Values ◽  
Research Effort ◽  
Rapid Development ◽  
Active Noise Control ◽  
Elastic Metamaterials ◽  
Wave Control

Over the past two decades, an extensive research effort has been devoted to elastic metamaterials, structured artificial materials at subwavelength scales, for elastic wave manipulations in solids. Due to the extreme values of material parameters, negative and/or positive, they achieved, the applications can range from wave and/or vibration attenuations, wave guiding and imaging, enhanced sensing, to invisible cloaking. However, conventional passive metamaterials have limitations, i.e. they can only be operated in narrow frequency regions and their functions are usually locked into space or with minor tunabilities once fabricated, lacking real time reconfigurabilities. Those limitations strongly hinder them from practical usages. With the rapid development of smart materials and structures, more and more intelligent elements are being introduced into wave propagation, vibration and sound control systems. The piezoelectric shunting technique is one well known method that receives considerable attention. In this dissertation, by leveraging the circuit control concept, both analog and digital, we propose some circuit controlled active/adaptive/hybrid/programmable metamaterials and metasurfaces for unprecedent elastic wave manipulations. Analytical, numerically and experimentally approaches are combined throughout the dissertation to illustrate design concepts, characterize wave propagation properties, and valid the designs. Specifically, active elastic metamaterials with tunable stiffness in local resonators are first designed for tunable wave and/or vibration mitigations. We then extend this concept to achieve super broadband wave attenuations with frequency-dependent stiffness elements. By introducing the variable stiffness elements to the host medium, a hybrid metamaterial is developed for switched ON/OFF wave propagations and broadband negative refractions. Based on a developed approximate transformation method, an active metamaterial is designed and placed on a plate to achieve spatially varying effective mass densities for broadband elastic trajectory control. Finally, a programmable metasurface with ultrathin-thickness is demonstrated for broadband, real-time and multifunctional wavefront manipulations in a plate. The active, adaptive, hybrid, and programmable elastic metamaterials and/or metasurfaces are still in their infant stages. The examples presented in the dissertation are transformable to different length and time scales and could serve as efficient and powerful tools in exploring some unconventional wave phenomenon in solid structures, i.e. by using concepts in quantum mechanics, where passive approaches are significantly limited. The designs could also immediately open new possibilities in elastic wave control devices including, but not limited to structural health monitoring, stealth technology, active noise control, as well as medical instrumentation and imaging.

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