Download or read book Controlling Acoustic and Elastic Waves with Metamaterials written by Xiaoshi Su and published by . This book was released on 2017 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this dissertation is to model, simulate and design metamaterials for underwater sound and elastic wave control. Water-based acoustic metamaterials usually suffer from low transmission due to the impedance mismatch with water; elastic metamaterials also suffer from this issue not only because of the impedance mismatch to the host medium, but also due to the multiple wave types existing simultaneously at the interface between the inclusions and the background matrix. This dissertation focuses on the theoretical modeling and computational design of broadband high transmission metamaterial devices. Several related topics are discussed. (1) A semi-analytical method for band diagram computation of three dimensional (3D) lattices is developed in this dissertation. It has significant applications in 3D pentamode metamaterial design. (2) Acoustic transmission through gratings of parallel plates displaying anisotropic inertia is also investigated. It is found that broadband impedance matching and total acoustic transmission can be achieved if the plane wave is incident at the so-called intromission angle ±[theta]i. (3) Elastic wave transmission through aligned parallel plates are studied theoretically by considering the coupling between different types of waves in elastic half-spaces and in the plates. The results are applied in the design and optimization of elastic metamaterials. (4) Elastic waves in fluid-saturated anisotropic double porosity medium of cubic symmetry is also investigated as an extension to Biot's theory of poroelasticity. A third dilatational wave is predicted in a double porosity fluid-saturated gyroid structure and demonstrated using finite element (FEM) simulations. The second part of the dissertation focuses on several novel devices for manipulating acoustic and elastic waves. Metallic metamaterial unit cells of the hexagonal lattice type are employed to mimic the quasi-static acoustic properties of water, and to provide a certain range of index for gradient index (GRIN) metamaterial design. The advantage of such a metamaterial element is that it has in-plane isotropy and only allows one propagating mode within the frequency range of interest. (5) A flat GRIN lens is designed by tuning the unit cells to obey a modified hyperbolic secant index profile, such that a normally incident plane wave transmits through the lens efficiently and focuses at a single point. The side lobe suppression and aberration reduction abilities of the GRIN lens are demonstrated in both simulations and in underwater experiments (carried out by colleagues at the University of Texas at Austin). (6) An elastic shell based metamaterial element, which provides a wider range of index at the quasi-static regime, is adopted in the design of a conformal lens for converting a monopole source to highly directional plane wave beams. The required bulk modulus and density distributions are derived using conformal transformation acoustics mapping from a unit circle to a triangle. The mapping function is adjustable which allows energy radiating preferentially into different directions. Two collimation devices are designed using fluid-saturated shells and demonstrated using full wave FEM simulations. (7) A novel class of elastic metamaterial composed of "effective plates" are introduced to design high transmission devices for elastic waves. Several devices for focusing SV-wave, splitting P- and SV-waves, and asymmetric transmission are designed and demonstrated using full wave FEM simulations.

Download or read book Programmable Elastic Metamaterials for Wave Control and Device Applications written by Hui Chen and published by Frontiers Media SA. This book was released on 2023-10-27 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emerging from electromagnetic waves and fast extending to acoustic and elastic waves, metamaterials that exhibit extraordinary wave control abilities have been gaining soaring attention. Over the past two decades, elastic metamaterials with engineered microstructures have provided a variety of appealing solutions for controlling elastic waves and vibrations. By tailoring their internal microstructures at a subwavelength scale, elastic metamaterials fruitfully distinct themselves from traditional materials or phononic crystals by their striking functions in wave trajectory manipulation, cloaking, nonreciprocal and topological wave control, as well as low-frequency wave/vibration mitigation and absorption.

Download or read book Fundamentals and Applications of Acoustic Metamaterials written by Vicente Romero-Garcia and published by John Wiley & Sons. This book was released on 2019-08-09 with total page 281 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Sound Topology Duality Coherence and Wave Mixing written by Pierre Deymier and published by Springer. This book was released on 2017-08-12 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers an essential introduction to the notions of sound wave topology, duality, coherence and wave-mixing, which constitute the emerging new science of sound. It includes general principles and specific examples that illuminate new non-conventional forms of sound (sound topology), unconventional quantum-like behavior of phonons (duality), radical linear and nonlinear phenomena associated with loss and its control (coherence), and exquisite effects that emerge from the interaction of sound with other physical and biological waves (wave mixing). The book provides the reader with the foundations needed to master these complex notions through simple yet meaningful examples. General principles for unraveling and describing the topology of acoustic wave functions in the space of their Eigen values are presented. These principles are then applied to uncover intrinsic and extrinsic approaches to achieving non-conventional topologies by breaking the time reversal symmetry of acoustic waves. Symmetry breaking can impart topological immunity to wave degradation from imperfection scattering and catalyze controlled coherence. In the intrinsic case and the phonon representation of acoustic waves, the self-interaction/interference of a wave through its supporting medium exposes the notion of duality in the quantum statistics (i.e. boson vs. fermion characterized by the symmetry of multiple particle states) and how the quantum analogue behaviors of sound can be exploited in the form of novel sound-based information transfer and processing devices. By considering media that mix different types of waves, the book addresses the interaction of sound with other physical and biological waves but also brings to light examples of extrinsic processes that can lead to symmetry breaking. The coherent conversion of sound into other types of waves as well as the sound-induced non-conventional topology of elastic, electronic, spin and biological waves are presented in the case of media exhibiting elasto-electronic, photo-elastic, magneto-elastic effects and biological mechano-transduction.

Download or read book Acoustic Metamaterials and Phononic Crystals written by Pierre A. Deymier and published by Springer Science & Business Media. This book was released on 2013-01-13 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Acoustic and Elastic Waves in Metamaterials for Underwater Applications written by Alexey S. Titovich and published by . This book was released on 2015 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Acoustics Based on Metamaterials written by Woon Siong Gan and published by Springer. This book was released on 2017-12-10 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Acoustic Metamaterials written by Richard V. Craster and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: About the book: This book is the first comprehensive review on 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. Most related books in the field address electromagnetic metamaterials and focus on numerical methods, and little (or no) experimental section. Each chapter will be authored by an acknowledged expert, amongst the topics covered will be experimental results on non-destructive imaging, cloaking by surface water waves, flexural waves in thin plates. Applications in medical ultrasound imaging and modeling of metamaterials will be emphasized too. The book can serve as a reference for researchers who wish to build a solid foundation of wave propagation in this class of novel materials.

Download or read book Acoustic Waves in Periodic Structures Metamaterials and Porous Media written by Noé Jiménez and published by Springer Nature. This book was released on 2021-11-03 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book delivers a comprehensive and up-to-date treatment of practical applications of metamaterials, structured media, and conventional porous materials. With increasing levels of urbanization, a growing demand for motorized transport, and inefficient urban planning, environmental noise exposure is rapidly becoming a pressing societal and health concern. Phononic and sonic crystals, acoustic metamaterials, and metasurfaces can revolutionize noise and vibration control and, in many cases, replace traditional porous materials for these applications. In this collection of contributed chapters, a group of international researchers reviews the essentials of acoustic wave propagation in metamaterials and porous absorbers with viscothermal losses, as well as the most recent advances in the design of acoustic metamaterial absorbers. The book features a detailed theoretical introduction describing commonly used modelling techniques such as plane wave expansion, multiple scattering theory, and the transfer matrix method. The following chapters give a detailed consideration of acoustic wave propagation in viscothermal fluids and porous media, and the extension of this theory to non-local models for fluid saturated metamaterials, along with a description of the relevant numerical methods. Finally, the book reviews a range of practical industrial applications, making it especially attractive as a white book targeted at the building, automotive, and aeronautic industries.

Download or read book Acoustic Metamaterials and Wave Control written by Gengkai Hu and published by Frontier Research in Computati. This book was released on 2020-11-30 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: As an emerging interdisciplinary field, acoustic metamaterials have generated increasing interests for diverse engineering applications, from noise and vibration alleviation to super-resolution imaging. The book starts with a simple mass-in-mass chain model to illustrate the concept of negative mass due to internal resonance and its impact on wave transmission. The practical transformation theory for controlling acoustic waves is explained. Pentamode acoustic metamaterials and related cloaking design are also included. Finally, the book ends up with the sub-diffraction-limited acoustic imaging based on metamaterials. This comprehensive title gives a broad overview on different aspects of acoustic metamaterials with a balance of theory and experiment. It is not only a collection of the authors' original works to these interesting topics, but also the main achievements in this field. Researchers, academics, professionals and graduate students in the fields of mechanical engineering, condensed matter physics, new materials, applied physics, and general readers of noise and vibration controls, will find this exciting book to be an indispensible reference material.

Download or read book Broadband Reconfigurable and Multifunctional Elastic Wave Control with Smart Metamaterials written by Yangyang Chen and published by . This book was released on 2017 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Acoustic Metamaterials written by Richard V. Craster and published by Springer. This book was released on 2012-12-05 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: About the book: This book is the first comprehensive review on 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. Most related books in the field address electromagnetic metamaterials and focus on numerical methods, and little (or no) experimental section. Each chapter will be authored by an acknowledged expert, amongst the topics covered will be experimental results on non-destructive imaging, cloaking by surface water waves, flexural waves in thin plates. Applications in medical ultrasound imaging and modeling of metamaterials will be emphasized too. The book can serve as a reference for researchers who wish to build a solid foundation of wave propagation in this class of novel materials.

Download or read book Acoustic fields and waves in solids written by B.A. Auld and published by Рипол Классик. This book was released on 1973 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume One begins with a systematic development of basic concepts (strain, stress, stiffness and compliance, viscous clamping) and coordinate transformations in both tensor and matrix notation. The basic elastic field equations are then written in a form analogous to Maxwell's equations. This analogy is then pursued when analyzing wave propagation in both isotropic and anisotropic solids. Piezoelectricity and bulk wave transducers are treated in the final chapter. Appendixes list slowness diagrams and material properties for various crystalline solids.

Download or read book Elastic Waves and Metamaterials The Fundamentals written by Yoon Young Kim and published by Springer Nature. This book was released on 2023-08-01 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book serves as an introductory text for students and engineers with limited knowledge of metamaterials (and elastic waves). This text begins with the most straightforward vibrating systems, such as single and 2-DOF spring-mass systems. It examines the observed phenomena in 2-DOF systems in an unconventional manner to prepare the reader for research on metamaterials. After presenting wave phenomena in an infinitely connected spring-mass system, an elastic bar, a continuous version of an infinite system, is analyzed. This instructional strategy, which progresses from the discrete model to the continuous model, facilitates efficient comprehension of wave and metamaterial concepts. Using continuous and discrete one-dimensional models, bending waves and their manipulation through metamaterials are also discussed. In the latter chapters of this book, advanced readers are introduced to the fundamental wave phenomena in two-dimensional media and wave manipulation using metamaterials, such as mode-converting transmission. As wave phenomena are the fundamental phenomena in vibrating structures, those interested in acoustics and vibration would gain a great deal of knowledge from this book, as the material covered in it offers a very different perspective on oscillatory phenomena than what is typically found in books on acoustics and vibration. Because this book presents a new technique for manipulating waves using metamaterials, engineers and scientists who work with (ultra)sounds and structural vibrations would find it very useful for expanding their knowledge of relevant topics.

Download or read book Time domain Modeling of Elastic and Acoustic Wave Propagation in Unbounded Media with Application to Metamaterials written by Hisham Assi and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Perfectly matched layers (PML) are a well-developed method for simulating wave propagation in unbounded media enabling the use of a reduced computational domain without having to worry about spurious boundary reflections. Many PML studies have been reported for both acoustic waves in fluids and elastic waves in solids. Nevertheless, further studies are needed for improvements in the fields of formulation, stability, and inhomogeneity of PMLs. This thesis introduces new second-order time-domain PML formulations for modeling mechanical wave propagation in unbounded solid, fluid, and coupled fluid-solid media. It also addresses certain stability issues, and demonstrates application of these formulations. Using a complex coordinate stretching approach a PML for the time-domain anisotropic elastic wave equation in two dimensional space is compactly formulated with two second- order equations along with only four auxiliary equations. This makes it smaller than existing formulations, thereby simplifying the problem and reducing the computational burden. A simple method is proposed for improving the stability of the discrete PML problem for a wide range of otherwise unstable anisotropic elastic media. Specifically, the value of the scaling parameter was increased thereby moving unstable modes out of the discretely resolved range of spatial frequencies. A new second-order time-domain PML formulation for fluid-solid heterogeneous media is presented. This formulation satisfies the interface coupling boundary conditions which were chosen such that they can be readily integrated into a weak formulation of the complete fluid-solid problem and which can be used in a finite element method (FEM) analysis. Numerical FEM results are given to establish the accuracy of the formulations and to provide examples of their application. In particular, numerical examples are shown to validate the elastic wave PML formulation and to illustrate the improved stability that can be achieved with certain anisotropic media that have known issues. In addition, the effectiveness of the fluid-solid PML is numerically demonstrated for absorbing all kinds of bulk waves, as well as surface and evanescent waves. Finally, the new formulations were used to predict the transient response of a solid phononic structure consisting of a superfocusing acoustic lens.

Download or read book Theory and Design of Acoustic Metamaterials written by Perngjin Frank Pai and published by . This book was released on 2015 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the most recent theoretical developments and numerical/experimental validations of new metamaterials and phononic crystals for the broadband absorption of elastic waves and vibrations in structures. These nine chapters explore many aspects of phononic crystals and acoustic/elastic metamaterials, including sound attenuation/absorption, extraordinary transmission, wave broadband mitigation, wave steering, cloaking via the transformation method, optimization of phononic crystals, and active acoustic metamaterials.

Download or read book Physics of Negative Refraction and Negative Index Materials written by Clifford M. Krowne and published by Springer Science & Business Media. This book was released on 2007-08-14 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the subject of optical and electronic negative refraction (NR) and negative index materials NIM). Diverse approaches for achieving NR and NIM are covered, such as using photonic crystals, phononic crystals, split-ring resonators (SRRs) and continuous media, focusing of waves, guided-wave behavior, and nonlinear effects. It is perhaps the most comprehensive book on the new class of negative refraction materials, covering all aspects of negative refraction and negative index materials.