Metamaterials In Topological Acoustics

Serves as a single resource on acoustic metamaterials and is the first book to discuss energy harvesting from metamaterials Covers the fundamentals of classical mechanics, quantum mechanics, and state-of-the-art condensed matter physics principles so that topological acoustics can be easily understood by engineers Introduces topological behaviors, acoustics hall effects, and applications Details smart materials and introduces different energy harvesting mechanisms for metamaterials followed by mechatronics packaging Explains the pros and cons of different design methods and gives guidelines for selecting specific designs of acoustic metamaterials with specific topological behaviors Includes MATLAB and Python code for numerical analysis

The revised edition of this book offers an expanded review of acoustic metamaterials; novel materials which can manipulate sound waves in surprising ways, which include collimation, focusing, cloaking, sonic screening and extraordinary transmission. It covers both experimental and theoretical aspects of acoustic and elastic waves propagating in structured composites, with a focus on effective properties associated with negative refraction, lensing and cloaking. Updated chapters cover filtering effects, extraordinary transmission, sub-wavelength imaging via tomography or time-reversal techniques, cloaking via transformation acoustics, elastodynamics, and acoustic scattering cancellation. For this revised edition, three new chapters have been introduced to reflect developments in experimental acoustics and metasurfaces, resonators atop surfaces and elastic metamaterials. The broad scope gives the reader an overview of the state of the art in acoustic metamaterials research and an indication of future directions and applications. It will serve as a solid introduction to the field for advanced students, and a valuable reference for those working in metamaterials and related areas.

In the last few decades, metamaterials have revolutionized the ways in which waves are controlled, and applied in physics and practical situations. The extraordinary properties of metamaterials, such as their locally resonant structure with deep subwavelength band gaps and their ranges of frequency where propagation is impossible, have opened the way to a host of applications that were previously unavailable. Acoustic metamaterials have been able to replace traditional treatments in several sectors, due to their better performance in targeted and tunable frequency ranges with strongly reduced dimensions. This is a training book composed of nine chapters written by experts in the field, giving a broad overview of acoustic metamaterials and their uses. The book is divided into three parts, covering the state-of-the-art, the fundamentals and the real-life applications of acoustic metamaterials.

This comprehensive book presents all aspects of acoustic metamaterials and phononic crystals. The emphasis is on acoustic wave propagation phenomena at interfaces such as refraction, especially unusual refractive properties and negative refraction. A thorough discussion of the mechanisms leading to such refractive phenomena includes local resonances in metamaterials and scattering in phononic crystals.

This thesis reports a rare combination of experiment and theory on the role of geometry in materials science. It is built on two significant findings: that curvature can be used to guide crack paths in a predictive way, and that protected topological order can exist in amorphous materials. In each, the underlying geometry controls the elastic behavior of quasi-2D materials, enabling the control of crack propagation in elastic sheets and the control of unidirectional waves traveling at the boundary of metamaterials. The thesis examines the consequences of this geometric control in a range of materials spanning many orders of magnitude in length scale, from amorphous macroscopic networks and elastic continua to nanoscale lattices.

Acoustic metamaterials are artificially designed and manufactured structures with dy-namical properties that are not typically found in naturally-occurring materials. The design of acoustic metamaterials is considered to be in its infancy but is progressively emerging to provide both scientists and engineers with a wide range of practical appli-cations, mostly dealing with acoustic waves' manipulation, thus becoming a key ena-bling technology to overcome a number of the near future scientific and engineering challenges. At present, the design of acoustic metamaterials is mainly done with proce-dures based on experience and results obtained from theoretical studies which have a lack of real practical application. In this context, cutting-edge computational design tools such as multiscale modelling, model order reduction and multiobjective optimiza-tion techniques can play an important role to unravel the design of more sophisticated and efficient acoustic metamaterials. The aim of this project is to set up the basis for the future development of sophisticated numerical tools for the design of acoustic met-amaterials. In this sense, the results presented here can be regarded as examples to better understand the concept of acoustic metamaterials and considered a review of the currently existing models and numerical techniques available for studying them.

This book derives physical models from basic principles, studies the effect of equivalent models on the dynamic characteristics of phononic crystals and acoustic metamaterials, and analyzes the physical mechanisms behind vibration and noise reduction. It first summarizes the research status of vibration and noise reduction, and research progress in phononic crystals and acoustic metamaterials. Based on this, one-dimensional periodic beam, two-dimensional thin plate with circular hole, and corresponding gradient structures are introduced, and their dynamic characteristics are discussed in detail. Therefore, different equivalent methods for different models are proposed through theoretical analysis, modal analysis and transmission rate analysis. Finally, a Helmholtz-type acoustic metamaterial, i.e. a multi-layer slotted tube acoustic metamaterial, is studied. Aiming at the low-frequency band gap of this model, a theoretical model for solving the inverse problem of acousto-electric analogue equivalent is proposed, and the effect of structural parameters on the low-frequency band gap is studied using this equivalent model. This book closely revolves around how to conduct equivalent research on artificially fabricated periodic structures. The methods and conclusions presented in this book provide a new theoretical basis for the application of artificial woven periodic structures in the field of low-frequency vibration reduction and noise reduction and are also an innovation in the discipline of vibration and noise control. This book is suitable for undergraduate students, graduate students and teachers in vibration and noise majors in universities, and can also provide references for engineering and technical personnel in related fields.

This book highlights the acoustical metamaterials’ capability to manipulate the direction of sound propagation in solids which in turn control the scattering, diffraction and refraction, the three basic mechanisms of sound propagation in solids. This gives rise to several novel theories and applications and hence the name new acoustics. As an introduction, the book mentions that symmetry of acoustic fields is the theoretical framework of acoustical metamaterials. This is then followed by describing that acoustical metamaterials began with locally resonant sonic materials which ushered in the concept of negative acoustic parameters such as mass density and bulk modulus. This complies with form invariance of the acoustic equation of motion which again exemplifies the symmetry property of acoustic fields.

This book presents a complete framework for energy harvesting technologies based on graded elastic metamaterials. First, it provides a comprehensive survey of state-of-the-art research on metamaterials for energy harvesting and then explores the theoretical wave mechanics framework, going from inhomogeneous media to graded elastic metamaterials. The framework can be used to thoroughly analyse wave propagation phenomena in beams, plates, and half-spaces and to investigate the effect of local resonance on creating bandgaps or wave mode conversions. All these concepts converge together with piezoelectric materials in the study and design of piezo-augmented arrays of resonators. The energy harvesting performances of the graded metamaterials are then compared to conventional solutions, in order to quantify their advantages for applications.