Download or read book An Experimental Exploration Study of Acoustic Black Holes in Thick Plates written by Emily Stimson and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: An Acoustic Black Hole (ABH) is an effect that occurs when a structure contains a power-law tapered thickness. This profile will create a means for vibrations to be focused into a thinner region of the structure, where the addition of a lossy material can help efficiently dissipate the vibrational energy, essentially "trapping" the vibrations. Embedding a set of damped ABHs into a structure then creates a metastructure with good vibration and noise reduction characteristics, but with a lower weight than traditional add-on treatments. For this project, four 1" thick aluminum panels with various ABH orientations, lengths, minimum thicknesses, and types are explored using experimental modal analysis and laser vibrometry. Each of the four panels contained one or multiple ABHs, labeled as an ABH or multi-grid panel, were compared to the mode shapes and loss factors of a Baseline panel. The frequencies for each of the first modes shapes, or "cut-on" frequencies, for the ABH and multi-grid panels all occurred at lower frequencies compared to the Baseline panel; even after adding a layer of polyurethane for damping to the Baseline and ABH panels, there was an observable downward shift in each panel's "cut-on" frequency compared to the undamped Baseline panel. All of the panels exhibited several different modal behaviors including: modes that were dominated by the geometry of the panel and the boundary conditions, modes that were dictated by the embedded ABHs in the panel, and a mixture between the two. This led to the investigation for the types of mode classifications: global, local, and mixed modes. Then comparing the general shapes, movements, and radiation efficiencies of the mode shapes to the likes of a piston, dipole, or quadrupole source. The panels' loss factors aided in this exploration, due to similar global and mixed modes appearing in the lower loss factor range, while particular locally focused modes were seen with loss factors clearly above the rest.
Download or read book Surface Acoustic Waves in Inhomogeneous Media written by Sergey V. Biryukov and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface Acoustic Waves in Inhomogeneous Media covers almost all important problems of the interaction of different types of surface acoustic waves with surface inhomogeneities. The problems of surface acoustic wave interaction with periodic topographic gratings widely used in filters and resonators are under careful consideration. The most important results of surface wave scattering by local defects such as grooves, random roughness, elastic wedges are given. Different theoretical approaches and practical rules for solving the surface wave problems are presented.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Vibration of Continuous Systems written by Singiresu S. Rao and published by John Wiley & Sons. This book was released on 2019-03-06 with total page 816 pages. Available in PDF, EPUB and Kindle. Book excerpt: A revised and up-to-date guide to advanced vibration analysis written by a noted expert The revised and updated second edition of Vibration of Continuous Systems offers a guide to all aspects of vibration of continuous systems including: derivation of equations of motion, exact and approximate solutions and computational aspects. The author—a noted expert in the field—reviews all possible types of continuous structural members and systems including strings, shafts, beams, membranes, plates, shells, three-dimensional bodies, and composite structural members. Designed to be a useful aid in the understanding of the vibration of continuous systems, the book contains exact analytical solutions, approximate analytical solutions, and numerical solutions. All the methods are presented in clear and simple terms and the second edition offers a more detailed explanation of the fundamentals and basic concepts. Vibration of Continuous Systems revised second edition: Contains new chapters on Vibration of three-dimensional solid bodies; Vibration of composite structures; and Numerical solution using the finite element method Reviews the fundamental concepts in clear and concise language Includes newly formatted content that is streamlined for effectiveness Offers many new illustrative examples and problems Presents answers to selected problems Written for professors, students of mechanics of vibration courses, and researchers, the revised second edition of Vibration of Continuous Systems offers an authoritative guide filled with illustrative examples of the theory, computational details, and applications of vibration of continuous systems.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1979 with total page 1696 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sound and Structural Vibration written by Frank J. Fahy and published by Elsevier. This book was released on 2007-01-12 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first edition of Sound and Structural Vibration was written in the early 1980s. Since then, two major developments have taken place in the field of vibroacoustics. Powerful computational methods and procedures for the numerical analysis of structural vibration, acoustical fields and acoustical interactions between fluids and structures have been developed and these are now universally employed by researchers, consultants and industrial organisations. Advances in signal processing systems and algorithms, in transducers, and in structural materials and forms of construction, have facilitated the development of practical means of applying active and adaptive control systems to structures for the purposes of reducing or modifying structural vibration and the associated sound radiation and transmission. In this greatly expanded and extensively revised edition, the authors have retained most of the analytically based material that forms the pedagogical content of the first edition, and have expanded it to present the theoretical foundations of modern numerical analysis. Application of the latter is illustrated by examples that have been chosen to complement the analytical approaches to solving fairly simple problems of sound radiation, transmission and fluid-structural coupling that are presented in the first edition. The number of examples of experimental data that relate to the theoretical content, and illustrate important features of vibroacoustic interaction, has been augmented by the inclusion of a selection from the vast amount of material published during the past twenty five years. The final chapter on the active control of sound and vibration has no precursor in the first edition. * Covers theoretical approaches to modeling and analysis* Highly applicable to challenges in industry and academia* For engineering students to use throughout their career
Download or read book Cymatics written by Hans Jenny and published by Macromedia. This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: An overview of the pioneering work done by Dr. Hans Jenny with audible vibration on various substances. His research had led to speculation about the origin of matter and its relation to vibration and sound.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 682 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analogue Gravity Phenomenology written by Daniele Faccio and published by Springer. This book was released on 2013-08-13 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: Analogue Gravity Phenomenology is a collection of contributions that cover a vast range of areas in physics, ranging from surface wave propagation in fluids to nonlinear optics. The underlying common aspect of all these topics, and hence the main focus and perspective from which they are explained here, is the attempt to develop analogue models for gravitational systems. The original and main motivation of the field is the verification and study of Hawking radiation from a horizon: the enabling feature is the possibility to generate horizons in the laboratory with a wide range of physical systems that involve a flow of one kind or another. The years around 2010 and onwards witnessed a sudden surge of experimental activity in this expanding field of research. However, building an expertise in analogue gravity requires the researcher to be equipped with a rather broad range of knowledge and interests. The aim of this book is to bring the reader up to date with the latest developments and provide the basic background required in order to appreciate the goals, difficulties, and success stories in the field of analogue gravity. Each chapter of the book treats a different topic explained in detail by the major experts for each specific discipline. The first chapters give an overview of black hole spacetimes and Hawking radiation before moving on to describe the large variety of analogue spacetimes that have been proposed and are currently under investigation. This introductory part is then followed by an in-depth description of what are currently the three most promising analogue spacetime settings, namely surface waves in flowing fluids, acoustic oscillations in Bose-Einstein condensates and electromagnetic waves in nonlinear optics. Both theory and experimental endeavours are explained in detail. The final chapters refer to other aspects of analogue gravity beyond the study of Hawking radiation, such as Lorentz invariance violations and Brownian motion in curved spacetimes, before concluding with a return to the origins of the field and a description of the available observational evidence for horizons in astrophysical black holes.
Download or read book Artificial Black Holes written by Mario Novello and published by World Scientific. This book was released on 2002-10-04 with total page 415 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physicists are pondering on the possibility of simulating black holes in the laboratory by means of various “analog models”. These analog models, typically based on condensed matter physics, can be used to help us understand general relativity (Einstein's gravity); conversely, abstract techniques developed in general relativity can sometimes be used to help us understand certain aspects of condensed matter physics. This book contains 13 chapters — written by experts in general relativity, particle physics, and condensed matter physics — that explore various aspects of this two-way traffic.
Download or read book Understanding Acoustics written by Steven L. Garrett and published by Springer. This book was released on 2017-02-24 with total page 913 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook provides a unified approach to acoustics and vibration suitable for use in advanced undergraduate and first-year graduate courses on vibration and fluids. The book includes thorough treatment of vibration of harmonic oscillators, coupled oscillators, isotropic elasticity, and waves in solids including the use of resonance techniques for determination of elastic moduli. Drawing on 35 years of experience teaching introductory graduate acoustics at the Naval Postgraduate School and Penn State, the author presents a hydrodynamic approach to the acoustics of sound in fluids that provides a uniform methodology for analysis of lumped-element systems and wave propagation that can incorporate attenuation mechanisms and complex media. This view provides a consistent and reliable approach that can be extended with confidence to more complex fluids and future applications. Understanding Acoustics opens with a mathematical introduction that includes graphing and statistical uncertainty, followed by five chapters on vibration and elastic waves that provide important results and highlight modern applications while introducing analytical techniques that are revisited in the study of waves in fluids covered in Part II. A unified approach to waves in fluids (i.e., liquids and gases) is based on a mastery of the hydrodynamic equations. Part III demonstrates extensions of this view to nonlinear acoustics. Engaging and practical, this book is a must-read for graduate students in acoustics and vibration as well as active researchers interested in a novel approach to the material.
Download or read book Numerical Sound Synthesis written by Stefan Bilbao and published by John Wiley & Sons. This book was released on 2009-09-03 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Digital sound synthesis has long been approached using standard digital filtering techniques. Newer synthesis strategies, however, make use of physical descriptions of musical instruments, and allow for much more realistic and complex sound production and thereby synthesis becomes a problem of simulation. This book has a special focus on time domain finite difference methods presented within an audio framework. It covers time series and difference operators, and basic tools for the construction and analysis of finite difference schemes, including frequency-domain and energy-based methods, with special attention paid to problems inherent to sound synthesis. Various basic lumped systems and excitation mechanisms are covered, followed by a look at the 1D wave equation, linear bar and string vibration, acoustic tube modelling, and linear membrane and plate vibration. Various advanced topics, such as the nonlinear vibration of strings and plates, are given an elaborate treatment. Key features: Includes a historical overview of digital sound synthesis techniques, highlighting the links between the various physical modelling methodologies. A pedagogical presentation containing over 150 problems and programming exercises, and numerous figures and diagrams, and code fragments in the MATLAB® programming language helps the reader with limited experience of numerical methods reach an understanding of this subject. Offers a complete treatment of all of the major families of musical instruments, including certain audio effects. Numerical Sound Synthesis is suitable for audio and software engineers, and researchers in digital audio, sound synthesis and more general musical acoustics. Graduate students in electrical engineering, mechanical engineering or computer science, working on the more technical side of digital audio and sound synthesis, will also find this book of interest.
Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1995 with total page 1100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1995 with total page 1100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Worlds New Horizons in Astronomy and Astrophysics written by National Research Council and published by National Academies Press. This book was released on 2011-02-04 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Driven by discoveries, and enabled by leaps in technology and imagination, our understanding of the universe has changed dramatically during the course of the last few decades. The fields of astronomy and astrophysics are making new connections to physics, chemistry, biology, and computer science. Based on a broad and comprehensive survey of scientific opportunities, infrastructure, and organization in a national and international context, New Worlds, New Horizons in Astronomy and Astrophysics outlines a plan for ground- and space- based astronomy and astrophysics for the decade of the 2010's. Realizing these scientific opportunities is contingent upon maintaining and strengthening the foundations of the research enterprise including technological development, theory, computation and data handling, laboratory experiments, and human resources. New Worlds, New Horizons in Astronomy and Astrophysics proposes enhancing innovative but moderate-cost programs in space and on the ground that will enable the community to respond rapidly and flexibly to new scientific discoveries. The book recommends beginning construction on survey telescopes in space and on the ground to investigate the nature of dark energy, as well as the next generation of large ground-based giant optical telescopes and a new class of space-based gravitational observatory to observe the merging of distant black holes and precisely test theories of gravity. New Worlds, New Horizons in Astronomy and Astrophysics recommends a balanced and executable program that will support research surrounding the most profound questions about the cosmos. The discoveries ahead will facilitate the search for habitable planets, shed light on dark energy and dark matter, and aid our understanding of the history of the universe and how the earliest stars and galaxies formed. The book is a useful resource for agencies supporting the field of astronomy and astrophysics, the Congressional committees with jurisdiction over those agencies, the scientific community, and the public.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2004 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Vibration Damping written by Ahid D. Nashif and published by John Wiley & Sons. This book was released on 1991-01-16 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: A practical approach to the application of viscoelastic damping materials to control vibration and noise problems in industrial structures, machinery, computer machinery, and vehicles. Assuming a basic understanding of mechanical engineering, the text covers implementation of theory, including material properties, dynamic structural response, design procedures and practical applications. Based on an understanding of both the properties of materials and the vibrational response of structures. Considers individual structures and the damping materials properties simultaneously. Includes extensive collection of data sheets for a large number of useful damping materials.
