The Science and Applications of Acoustics the Science and Applications of Acoustics
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Nonlinear Acoustics Applied to Nondestructive Testing
TO NONDESTRUCTIVE TESTING NONDESTRUCTIVE TO APPLIED ACOUSTICS NONLINEAR ABSTRACT Sensitive nonlinear acoustic methods are suitable But it is in general difficult to limit the geometrical for material characterization. This thesis describes extent of low-frequency acoustic waves. A techni- NONLINEAR ACOUSTICS APPLIED three nonlinear acoustic methods that are proven que is presented that constrains the wave field to useful for detection of defects like cracks and de- a localized trapped mode so that damage can be TO NONDESTRUCTIVE TESTING laminations in solids. They offer the possibility to located. use relatively low frequencies which is advanta- geous because attenuation and diffraction effects Keywords: nonlinear acoustics, nondestructive tes- are smaller for low frequencies. Therefore large ting, activation density, slow dynamics, resonance and multi-layered complete objects can be investi- frequency, nonlinear wave modulation spectros- gated in about one second. copy, harmonic generation, trapped modes, open Sometimes the position of the damage is required. resonator, sweep rate. Kristian Haller Kristian Haller Blekinge Institute of Technology Licentiate Dissertation Series No. 2007:07 2007:07 ISSN 1650-2140 School of Engineering 2007:07 ISBN 978-91-7295-119-8 Nonlinear Acoustics Applied to NonDestructive Testing Kristian Haller Blekinge Institute of Technology Licentiate Dissertation Series No 2007:07 ISSN 1650-2140 ISBN 978-91-7295-119-8 Nonlinear Acoustics Applied to NonDestructive Testing Kristian Haller Department of Mechanical Engineering School of Engineering Blekinge Institute of Technology SWEDEN © 2007 Kristian Haller Department of Mechanical Engineering School of Engineering Publisher: Blekinge Institute of Technology Printed by Printfabriken, Karlskrona, Sweden 2007 ISBN 978-91-7295-119-8 Acknowledgements This work was carried out at the Department of Mechanical Engineering, Blekinge Institute of Technology, Karlskrona, Sweden. -
An Adaptive Tuning System for MIDI Pianos
David Løberg Code Groven.Max: School of Music Western Michigan University Kalamazoo, MI 49008 USA An Adaptive Tuning [email protected] System for MIDI Pianos Groven.Max is a real-time program for mapping a renstemningsautomat, an electronic interface be- performance on a standard keyboard instrument to tween the manual and the pipes with a kind of arti- a nonstandard dynamic tuning system. It was origi- ficial intelligence that automatically adjusts the nally conceived for use with acoustic MIDI pianos, tuning dynamically during performance. This fea- but it is applicable to any tunable instrument that ture overcomes the historic limitation of the stan- accepts MIDI input. Written as a patch in the MIDI dard piano keyboard by allowing free modulation programming environment Max (available from while still preserving just-tuned intervals in www.cycling74.com), the adaptive tuning logic is all keys. modeled after a system developed by Norwegian Keyboard tunings are compromises arising from composer Eivind Groven as part of a series of just the intersection of multiple—sometimes oppos- intonation keyboard instruments begun in the ing—influences: acoustic ideals, harmonic flexibil- 1930s (Groven 1968). The patch was first used as ity, and physical constraints (to name but three). part of the Groven Piano, a digital network of Ya- Using a standard twelve-key piano keyboard, the maha Disklavier pianos, which premiered in Oslo, historical problem has been that any fixed tuning Norway, as part of the Groven Centennial in 2001 in just intonation (i.e., with acoustically pure tri- (see Figure 1). The present version of Groven.Max ads) will be limited to essentially one key. -
The Standing Acoustic Wave Principle Within the Frequency Analysis Of
inee Eng ring al & ic d M e e d Misun, J Biomed Eng Med Devic 2016, 1:3 m i o c i a B l D f o e v DOI: 10.4172/2475-7586.1000116 l i a c n e r s u o Journal of Biomedical Engineering and Medical Devices J ISSN: 2475-7586 Review Article Open Access The Standing Acoustic Wave Principle within the Frequency Analysis of Acoustic Signals in the Cochlea Vojtech Misun* Department of Solid Mechanics, Mechatronics and Biomechanics, Brno University of Technology, Brno, Czech Republic Abstract The organ of hearing is responsible for the correct frequency analysis of auditory perceptions coming from the outer environment. The article deals with the principles of the analysis of auditory perceptions in the cochlea only, i.e., from the overall signal leaving the oval window to its decomposition realized by the basilar membrane. The paper presents two different methods with the function of the cochlea considered as a frequency analyzer of perceived acoustic signals. First, there is an analysis of the principle that cochlear function involves acoustic waves travelling along the basilar membrane; this concept is one that prevails in the contemporary specialist literature. Then, a new principle with the working name “the principle of standing acoustic waves in the common cavity of the scala vestibuli and scala tympani” is presented and defined in depth. According to this principle, individual structural modes of the basilar membrane are excited by continuous standing waves of acoustic pressure in the scale tympani. Keywords: Cochlea function; Acoustic signals; Frequency analysis; The following is a description of the theories in question: Travelling wave principle; Standing wave principle 1. -
Nuclear Acoustic Resonance Investigations of the Longitudinal and Transverse Electron-Lattice Interaction in Transition Metals and Alloys V
NUCLEAR ACOUSTIC RESONANCE INVESTIGATIONS OF THE LONGITUDINAL AND TRANSVERSE ELECTRON-LATTICE INTERACTION IN TRANSITION METALS AND ALLOYS V. Müller, G. Schanz, E.-J. Unterhorst, D. Maurer To cite this version: V. Müller, G. Schanz, E.-J. Unterhorst, D. Maurer. NUCLEAR ACOUSTIC RESONANCE INVES- TIGATIONS OF THE LONGITUDINAL AND TRANSVERSE ELECTRON-LATTICE INTERAC- TION IN TRANSITION METALS AND ALLOYS. Journal de Physique Colloques, 1981, 42 (C6), pp.C6-389-C6-391. 10.1051/jphyscol:19816113. jpa-00221175 HAL Id: jpa-00221175 https://hal.archives-ouvertes.fr/jpa-00221175 Submitted on 1 Jan 1981 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. JOURNAL DE PHYSIQUE CoZZoque C6, suppZe'ment au no 22, Tome 42, de'cembre 1981 page C6-389 NUCLEAR ACOUSTIC RESONANCE INVESTIGATIONS OF THE LONGITUDINAL AND TRANSVERSE ELECTRON-LATTICE INTERACTION IN TRANSITION METALS AND ALLOYS V. Miiller, G. Schanz, E.-J. Unterhorst and D. Maurer &eie Universit8G Berlin, Fachbereich Physik, Kiinigin-Luise-Str.28-30, 0-1000 Berlin 33, Gemany Abstract.- In metals the conduction electrons contribute significantly to the acoustic-wave-induced electric-field-gradient-tensor (DEFG) at the nuclear positions. Since nuclear electric quadrupole coupling to the DEFG is sensi- tive to acoustic shear modes only, nuclear acoustic resonance (NAR) is a par- ticularly useful tool in studying the coup1 ing of electrons to shear modes without being affected by volume dilatations. -
Research on the History of Modern Acoustics François Ribac, Viktoria Tkaczyk
Research on the history of modern acoustics François Ribac, Viktoria Tkaczyk To cite this version: François Ribac, Viktoria Tkaczyk. Research on the history of modern acoustics. Revue d’Anthropologie des Connaissances, Société d’Anthropologie des Connaissances, 2019, Musical knowl- edge, science studies, and resonances, 13 (3), pp.707-720. 10.3917/rac.044.0707. hal-02423917 HAL Id: hal-02423917 https://hal.archives-ouvertes.fr/hal-02423917 Submitted on 26 Dec 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. RESEARCH ON THE HISTORY OF MODERN ACOUSTICS Interview with Viktoria Tkaczyk, director of the Epistemes of Modern Acoustics research group at the Max Planck Institute for the History of Science, Berlin François Ribac S.A.C. | « Revue d'anthropologie des connaissances » 2019/3 Vol. 13, No 3 | pages 707 - 720 This document is the English version of: -------------------------------------------------------------------------------------------------------------------- François Ribac, « Recherche en histoire de l’acoustique moderne », Revue d'anthropologie -
Using the Partial Wave Method for Wave Structure Calculation and the Conceptual Interpretation of Elastodynamic Guided Waves
applied sciences Article Using the Partial Wave Method for Wave Structure Calculation and the Conceptual Interpretation of Elastodynamic Guided Waves Christopher Hakoda and Cliff J. Lissenden * Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, PA 16802, USA; [email protected] * Correspondence: [email protected] Received: 8 May 2018; Accepted: 8 June 2018; Published: 12 June 2018 Featured Application: Shortcut to wave-structure calculation for elastodynamic guided waves and prediction of acoustic leakage behavior. Abstract: The partial-wave method takes advantage of the Christoffel equation’s generality to represent waves within a waveguide. More specifically, the partial-wave method is well known for its usefulness when calculating dispersion curves for multilayered and/or anisotropic plates. That is, it is a vital component of the transfer-matrix method and the global-matrix method, which are used for dispersion curve calculation. The literature suggests that the method is also exceptionally useful for conceptual interpretation, but gives very few examples or instruction on how this can be done. In this paper, we expand on this topic of conceptual interpretation by addressing Rayleigh waves, Stoneley waves, shear horizontal waves, and Lamb waves. We demonstrate that all of these guided waves can be described using the partial-wave method, which establishes a common foundation on which many elastodynamic guided waves can be compared, translated, and interpreted. For Lamb waves specifically, we identify the characteristics of guided wave modes that have not been formally discussed in the literature. Additionally, we use what is demonstrated in the body of the paper to investigate the leaky characteristics of Lamb waves, which eventually leads to finding a correlation between oblique bulk wave propagation in the waveguide and the transmission amplitude ratios found in the literature. -
Acoustics & Ultrasonics
Dr.R.Vasuki Associate professor & Head Department of Physics Thiagarajar College of Engineering Madurai-625015 Science of sound that deals with origin, propagation and auditory sensation of sound. Sound production Propagation by human beings/machines Reception Classification of Sound waves Infrasonic audible ultrasonic Inaudible Inaudible < 20 Hz 20 Hz to 20,000 Hz ˃20,000 Hz Music – The sound which produces rhythmic sensation on the ears Noise-The sound which produces jarring & unpleasant effect To differentiate sound & noise Regularity of vibration Degree of damping Ability of ear to recognize the components Sound is a form of energy Sound is produced by the vibration of the body Sound requires a material medium for its propagation. When sound is conveyed from one medium to another medium there is no bodily motion of the medium Sound can be transmitted through solids, liquids and gases. Velocity of sound is higher in solids and lower in gases. Sound travels with velocity less than the velocity 8 of light. c= 3x 10 V0 =330 m/s at 0° degree Lightning comes first than thunder VT= V0+0.6 T Sound may be reflected, refracted or scattered. It undergoes diffraction and interference. Pitch or frequency Quality or timbre Intensity or Loudness Pitch is defined as the no of vibrations/sec. Frequency is a physical quantity but pitch is a physiological quantity. Mosquito- high pitch Lion- low pitch Quality or timbre is the one which helps to distinguish between the musical notes emitted by the different instruments or voices even though they have the same pitch. Intensity or loudness It is the average rate of flow of acoustic energy (Q) per unit area(A) situated normally to the direction of propagation of sound waves. -
Acoustic Textiles - the Case of Wall Panels for Home Environment
Acoustic Textiles - The case of wall panels for home environment Bachelor Thesis Work Bachelor of Science in Engineering in Textile Technology Spring 2013 The Swedish school of Textiles, Borås, Sweden Report number: 2013.2.4 Written by: Louise Wintzell, Ti10, [email protected] Abstract Noise has become an increasing public health problem and has become serious environment pollution in our daily life. This indicates that it is in time to control and reduce noise from traffic and installations in homes and houses. Today a plethora of products are available for business, but none for the private market. The project describes a start up of development of a sound absorbing wall panel for the private market. It will examine whether it is possible to make a wall panel that can lower the sound pressure level with 3 dB, or reach 0.3 s in reverberation time, in a normally furnished bedroom and still follow the demands of price and environmental awareness. To start the project a limitation was made to use the textiles available per meter within the range of IKEA. The test were made according to applicable standards and calculation of reverberation time and sound pressure level using Sabine’s formula and a formula for sound pressure equals sound effect. During the project, tests were made whether it was possible to achieve a sound classification C on a A-E grade scale according to ISO 11654, where A is the best, with only textiles or if a classic sound absorbing mineral wool had to be used. To reach a sound classification C, a weighted sound absorption coefficient (αw) of 0.6 as a minimum must be reached. -
Linear and Nonlinear Waves
Scholarpedia, 4(7):4308 www.scholarpedia.org Linear and nonlinear waves Graham W. Griffithsy and William E. Schiesser z City University,UK; Lehigh University, USA. Received April 20, 2009; accepted July 9, 2009 Historical Preamble The study of waves can be traced back to antiquity where philosophers, such as Pythagoras (c.560-480 BC), studied the relation of pitch and length of string in musical instruments. However, it was not until the work of Giovani Benedetti (1530-90), Isaac Beeckman (1588-1637) and Galileo (1564-1642) that the relationship between pitch and frequency was discovered. This started the science of acoustics, a term coined by Joseph Sauveur (1653-1716) who showed that strings can vibrate simultaneously at a fundamental frequency and at integral multiples that he called harmonics. Isaac Newton (1642-1727) was the first to calculate the speed of sound in his Principia. However, he assumed isothermal conditions so his value was too low compared with measured values. This discrepancy was resolved by Laplace (1749-1827) when he included adiabatic heating and cooling effects. The first analytical solution for a vibrating string was given by Brook Taylor (1685-1731). After this, advances were made by Daniel Bernoulli (1700-82), Leonard Euler (1707-83) and Jean d'Alembert (1717-83) who found the first solution to the linear wave equation, see section (3.2). Whilst others had shown that a wave can be represented as a sum of simple harmonic oscillations, it was Joseph Fourier (1768-1830) who conjectured that arbitrary functions can be represented by the superposition of an infinite sum of sines and cosines - now known as the Fourier series. -
Psychoacoustics Perception of Normal and Impaired Hearing with Audiology Applications Editor-In-Chief for Audiology Brad A
PSYCHOACOUSTICS Perception of Normal and Impaired Hearing with Audiology Applications Editor-in-Chief for Audiology Brad A. Stach, PhD PSYCHOACOUSTICS Perception of Normal and Impaired Hearing with Audiology Applications Jennifer J. Lentz, PhD 5521 Ruffin Road San Diego, CA 92123 e-mail: [email protected] Website: http://www.pluralpublishing.com Copyright © 2020 by Plural Publishing, Inc. Typeset in 11/13 Adobe Garamond by Flanagan’s Publishing Services, Inc. Printed in the United States of America by McNaughton & Gunn, Inc. All rights, including that of translation, reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, recording, or otherwise, including photocopying, recording, taping, Web distribution, or information storage and retrieval systems without the prior written consent of the publisher. For permission to use material from this text, contact us by Telephone: (866) 758-7251 Fax: (888) 758-7255 e-mail: [email protected] Every attempt has been made to contact the copyright holders for material originally printed in another source. If any have been inadvertently overlooked, the publishers will gladly make the necessary arrangements at the first opportunity. Library of Congress Cataloging-in-Publication Data Names: Lentz, Jennifer J., author. Title: Psychoacoustics : perception of normal and impaired hearing with audiology applications / Jennifer J. Lentz. Description: San Diego, CA : Plural Publishing, -
MTO 20.2: Wild, Vicentino's 31-Tone Compositional Theory
Volume 20, Number 2, June 2014 Copyright © 2014 Society for Music Theory Genus, Species and Mode in Vicentino’s 31-tone Compositional Theory Jonathan Wild NOTE: The examples for the (text-only) PDF version of this item are available online at: http://www.mtosmt.org/issues/mto.14.20.2/mto.14.20.2.wild.php KEYWORDS: Vicentino, enharmonicism, chromaticism, sixteenth century, tuning, genus, species, mode ABSTRACT: This article explores the pitch structures developed by Nicola Vicentino in his 1555 treatise L’Antica musica ridotta alla moderna prattica . I examine the rationale for his background gamut of 31 pitch classes, and document the relationships among his accounts of the genera, species, and modes, and between his and earlier accounts. Specially recorded and retuned audio examples illustrate some of the surviving enharmonic and chromatic musical passages. Received February 2014 Table of Contents Introduction [1] Tuning [4] The Archicembalo [8] Genus [10] Enharmonic division of the whole tone [13] Species [15] Mode [28] Composing in the genera [32] Conclusion [35] Introduction [1] In his treatise of 1555, L’Antica musica ridotta alla moderna prattica (henceforth L’Antica musica ), the theorist and composer Nicola Vicentino describes a tuning system comprising thirty-one tones to the octave, and presents several excerpts from compositions intended to be sung in that tuning. (1) The rich compositional theory he develops in the treatise, in concert with the few surviving musical passages, offers a tantalizing glimpse of an alternative pathway for musical development, one whose radically augmented pitch materials make possible a vast range of novel melodic gestures and harmonic successions. -
Arxiv:1912.02281V1 [Math.NA] 4 Dec 2019
A HIGH-ORDER DISCONTINUOUS GALERKIN METHOD FOR NONLINEAR SOUND WAVES PAOLA. F. ANTONIETTI1, ILARIO MAZZIERI1, MARKUS MUHR∗;2, VANJA NIKOLIC´ 3, AND BARBARA WOHLMUTH2 1MOX, Dipartimento di Matematica, Politecnico di Milano, Milano, Italy 2Department of Mathematics, Technical University of Munich, Germany 3Department of Mathematics, Radboud University, The Netherlands Abstract. We propose a high-order discontinuous Galerkin scheme for nonlinear acoustic waves on polytopic meshes. To model sound propagation with and without losses, we use Westervelt's nonlinear wave equation with and without strong damping. Challenges in the numerical analysis lie in handling the nonlinearity in the model, which involves the derivatives in time of the acoustic velocity potential, and in preventing the equation from degenerating. We rely in our approach on the Banach fixed-point theorem combined with a stability and convergence analysis of a linear wave equation with a variable coefficient in front of the second time derivative. By doing so, we derive an a priori error estimate for Westervelt's equation in a suitable energy norm for the polynomial degree p ≥ 2. Numerical experiments carried out in two-dimensional settings illustrate the theoretical convergence results. In addition, we demonstrate efficiency of the method in a three- dimensional domain with varying medium parameters, where we use the discontinuous Galerkin approach in a hybrid way. 1. Introduction Nonlinear sound waves arise in many different applications, such as medical ultra- sound [20, 35, 44], fatigue crack detection [46, 48], or musical acoustics of brass instru- ments [10, 23, 38]. Although considerable work has been devoted to their analytical stud- ies [29, 30, 33, 37] and their computational treatment [27, 34, 42, 51], rigorous numerical analysis of nonlinear acoustic phenomena is still largely missing from the literature.