INTERNATIONAL SOUND AND VIBRATION DIGEST (ISVD)
Published by THE INTERNATIONAL INSTITUTE OF ACOUSTICS AND VIBRATION (IIAV)
Volume 12, Number 1
Date: 10 February 2011
The information published in this digest has been submitted to ISVD from various sources and does not necessarily reflect the opinion of the IIAV.
Editor-in-Chief: Malcolm J. Crocker, Auburn University, USA Managing Editor: Margarita Maksotskaya, Auburn University, USA
Jorge P. Arenas [Chile],
António P. O. Carvalho [Portugal]
Luis Bento Coelho [Portugal]
Tamer Elnady [Egypt]
Leonid Gelman [United Kingdom]
Samir Gerges [Brazil]
Barry Gibbs [United Kingdom]
Jeong-Guon Ih [South Korea]
Colin Hansen [Australia]
Robin Langley [United Kingdom]
Juri Lavrentjev [Estonia]
Marek Pawelczyk [Poland]
Brian Mace [United Kingdom]
Nuno Maia [Portugal]
Chris K. Mechefske [Canada]
Ricardo E. Musafir [Brazil]
Haisam Osman [United States]
Bert Roozen [Netherlands]
Andrew F. Seybert [United States]
Sergey V. Sorokin [Denmark]
Rupert M. Thornely-Taylor [United Kingdom] Jiri Tuma [Czech Republic]
Current number of subscribers: 21,137
To send a submission to the International Sound and Vibration Digest (ISVD) please send your information by E-mail to email@example.com. In order to unsubscribe please reply to this message with unsubscribe in the subject to firstname.lastname@example.org.
TODAY\'S DIGEST CONTENTS
ITEM 1. INTRODUCTION.
ITEM 2. ICSV 18 CONGRESS: The Eighteenth International Congress on Sound and Vibration, Rio-de-Janeiro, Brazil, 10 to 14 July 2011.
ITEM 3. CONFERENCE ANNOUNCEMENTS: 1) International Digital laboratory, Warwick Manufacturing Group (WMG), University of Warwick Workshop, UK, March 29, 2011. 2) Alberta and Acoustics Noise Association (AANA) 2011 Spring Noise Conference, the Province of Alberta, Canada, May 24, 2011; 3) First International Conference on Cognitive Hearing Science for Communication, June 19-22, 2011, Linkoping, Sweden; 4) 11th International Conference on Vibration Problems (ICOVP)September 5-8, Prague, Czech Republic; 5)7th annual COMSOL Conference October 13-15, 2011, Boston, USA; 6)Fifth International Symposium on Temporal Design at University of Sheffield, July 21-22, 2011, Sheffield, UK; 7) The Conference of the Australian Acoustical Society Breaking New Ground November 2-4 2011, Holiday Inn, Surfers Paradise, Queensland Australia.
ITEM 4. NATIONAL ACOUSTICAL LABORATORIES AND RESEARCH ACTIVITIES: 1) Studies on human echolocation Cordoba Research and Transfer Center on Acoustics (CINTRA), Cordoba, Argentina; 2) The research project Human response to vibration in residential environment the University of Salford, UK; 3) Aeroacoustics Research at the University Of Adelaide, Australia. 4) Vibration Analysis in Light Synchrotrond. 5) NWAA Labs Seattle, Washington.
ITEM 5. NEW BOOK ANNOUNCEMENTS: 1) Command Generation for Dynamic Systems; 2) Hilbert Transform Applications in Mechanical Vibration; 3) Introduction to Finite Element Vibration Analysis Second Edition.
ITEM 6. RECENT DOCTORAL THESES: 1) Theoretical and experimental modal analysis of nonlinear vibrating structures using nonlinear normal modes; 2) Tuning methodology of nonlinear vibration absorbers coupled to nonlinear mechanical systems
ITEM 7. HONORS AND AWARDS: 1) INCE/USA Announces the Leo Beranek Student Medal for Excellence in the Study of Noise Control; 2) Matthew A. Davies, Ph.D. Associate Professor of Mechanical Engineering: (1) Bank of America Teaching Award Finalist;(2) Elected Fellow of the International Academy for Production Engineering Research; 3) Marek Pawelczyk appointed as Honorary Ambassador for Congresses of Poland.
ITEM 8. RESEARCH POSITION AVAILABLE: A Post-Doctoral research fellow in acoustics/vibrations, School of Mechanical Engineering, University of Adelaide, Australia.
ITEM 9. INDUSTRIAL NEWS. Marshall Day Acoustics releases North American version of INSUL v6.4.
>>> ITEM 10. NEW PATENT SPECIFICATION: Roundffusor1 (R1) - the complete acoustical material R1.
ITEM 11. IIAV: MEMBERSHIP APPLICATION FORM
ITEM 1. INTRODUCTION.
We are pleased to bring you the February 2011 issue of the INTERNATIONAL SOUND AND VIBRATION DIGEST (ISVD). The DIGEST is now being published by the INTERNATIONAL INSTITUTE OF ACOUSTICS AND VIBRATION (IIAV). The digest is free of charge to members of the IIAV. Non-members may also receive the digest in future if they log on at the IIAV website. The IIAV is a democratic international scientific society. Membership, as member or associate is open to individuals from all countries. In addition, 36 scientific societies and institutes have become affiliated with the IIAV as cooperating organizations. On behalf of Professor Hans Boden, KTH, Stockholm, Sweden, the President of the IIAV, and the officers and directors, it is our pleasure to invite you to consider becoming a member if you are not already. Members receive, as part of their annual dues of $80 USD, not only the ISVD but also a refereed journal, the INTERNATIONAL JOURNAL OF ACOUSTICS AND VIBRATION (IJAV) which began publication in December 1996. Members also receive each year the proceedings of the International Congress on Sound and Vibration (ICSV). Non-IIAV members and libraries can subscribe to the JOURNAL (IJAV) for $100 per year by airmail, post paid. Complete details about IIAV are available on the worldwide web at http://www.iiav.org. A membership application form is enclosed as ITEM 11 of this issue. It can be submitted by e-mail, fax or airmail.The proceedings of the previous congresses are available for a fee to non-members. If you are interested in further information, please go to www.iiav.org or write to email@example.com.
We are pleased to inform you that back issues of the ISV Digest are available on the IIAV website.
We hope that you are finding the INTERNATIONAL SOUND AND VIVRATION DIGEST useful. We should be interested to hear your comments and to receive news items and technical information and articles for inclusion in the next issue. We hope to bring out the next issue of the DIGEST in April 2011, so do not forget to send your news items soon! These should be sent to firstname.lastname@example.org.
Malcolm J. Crocker
ITEM 2. ICSV 18 CONGRESS: The Eighteenth International Congress on Sound and Vibration, Rio-de-Janeiro, Brazil, 10 to 14 July 2011. More than 650 abstracts have been submitted. The website will be open for correction to abstracts and late submission until February 15, 2011. For more information and to correct or submit an abstract please go to the ICSV 18 website: http://www.icsv18.org/
ITEM 3. CONFERENCE ANNOUNCEMENTS:
1) International Digital laboratory, Warwick Manufacturing Group (WMG), University of Warwick Workshop, UK March 29, 2011.
Engineering Integrity Society Technologies for Low Carbon Transportation in New Sound Environments The Engineering Integrity Society The Engineering Integrity Society is an independent not for profit organisation which aims to inspire newly qualified engineers to embrace engineering as their chosen profession. The Society is committed to promoting events and publications, providing a forum for experienced and new engineers to discuss present industrial needs, new technologies, and to stimulate both company and personal development. The annual subscription rates are £25 for UK residents and £30 for non UK residents. Upon joining the Society you will also have the additional advantages of; preferential attendance rates at EIS events, together with selected events held by some of the associated organisations. Access to archive CDs containing copies of EIS presentations. Warwick Innovative Manufacturing Research Center (WIMRC) Warwick Innovative Manufacturing Research Centre (WIMRC) was established at the University of Warwick in 2001 to fund and manage adventurous, multi disciplinary research relevant to the future needs of UK organisations competing in the global marketplace. It is funded by the Engineering and Physical Sciences Research Council (EPSRC) with supplementary support from industrial partners. WIMRC carries out research that supports the UK manufacturing industry, focusing on four key areas: Intelligent Vehicles; Eco Friendly Vehicles; Next Generation Healthcare Technology; Next Generation Healthcare Management. For Further Information please contact Lisa Mansfield by E-mail: email@example.com
2) Alberta Acoustics and Noise Association (AANA) Spring Noise Conference in the Province of Alberta, Canada, May 24, 2011.
The Alberta Acoustics and Noise Association will host workshops on the practical understanding and application of noise regulations in the Province of Alberta on May 24, 2011. These workshops begin at four day program including workshops, technical sessions and plenary speakers providing a forum for facility representatives to practiced acoustical consultants, to engage in discussions on noise control and regulation. The Spring Noise Conference is unique in its approach to present noise as a practical and applied topic for industry, acoustical specialists and practitioners alike and is the only conference in Canada to do so. Since its inception in 1993 the Spring Noise conference has grown from a local event initiated by the ERCB to a global conference that attracts attendees and speakers from around the world. Conference participants share experiences and innovations in environmental and occupational noise, sound measurement, regulation and control. This year plenary speakers specialties include wind turbine noise, low frequency noise, drilling noise, environmental noise regulation, noise control technologies, acoustical ecology and industrial hygiene. The 2011 Spring Noise Conference runs from May 24th-27th, 2011 at the Fairmont Banff Springs Hotel. Please visit www.springnoiseconference.com For more information please contact:
Robin Himes: firstname.lastname@example.org
Alberta Acoustics & Noise Association
3) First International Conference on Cognitive Hearing Science for Communication, Linkoping, Sweden, June 19-22, 2011.
Researchers in all fields, basic and applied, who are interested in the interplay between cognitive and hearing factors in communication, are welcome to attend. When the language input is degraded (due to challenging conditions, sensory impairment, or processing applied by hearing aids or implants), the quality of the \'bottom-up\' signal may not be sufficient to yield accurate perception, and the individual may rely on a variety of compensatory top down processes, based on cognitive abilities, and on knowledge and experience, to optimize understanding. Increased perceptual processing demands may also tax higher-level cognitive processing. The goal of this meeting is to describe, for persons with and without hearing impairment and for the profoundly deaf, how cognitive and compensatory factors interact with processing of the \'bottom-up\' signal in communication, and how this may change over the lifespan. The conference will include invited speakers and open poster sessions. Further information can be obtained from: http://eventus.trippus.se/head2011attendees. The conference is organized through the Linnaeus Center for Hearing and Deafness (Linnaeus HEAD), funded by a 10-year Linnaeus Grant from the Swedish Research Council (Vetenskapsradet)
4) 11th International Conference on Vibration Problems (ICOVP) Prague, Czech Republic, September 5-8, 2011.
The Permanent Committee of International Conference on Vibration Problems (ICOVP) and the Technical University of Liberec are pleased to announce the 10th biennial International Conference on Vibration Problems (ICOVP) 2011 to be held in Prague, Czech Republic, from 5 to 8 September, 2011. ICOVP-2011 aims to bring together scientists with different backgrounds who are actively engaged and working on vibration-related problems in all engineering disciplines, both in theoretical and applied fields. For more information, please visit: http://www.icovp.org/.
5) 7th annual COMSOL Conference October 13-15, 2011, Boston, USA.
The 7th annual COMSOL Conference 2011 will take place on October 13-15 2011 at the Boston Newton Marriott Newton, MA. The COMSOL Group provides software solutions for multiphysics modeling. We are a fast growing high tech engineering Software Company with a proven track record and a vision as a future leader of the industry. The company was founded in July 1986 in Stockholm, Sweden. We have grown to include offices in Denmark, Finland, France, Germany, the Netherlands, Norway, India, Italy, Switzerland, the United Kingdom, and the U.S.A. Conference Highlights include: User Presentations and Minicourses; Keynote Talks; Poster Session; Exhibition; Networking. Further Information and abstract submission can be sent to the COMSOL Conference 2011 website:
6) Fifth International Symposium on Temporal Design at University of Sheffield, Sheffield, UK, July 21-22, 2011.
Description: A joint event organized by the School of Architecture, University of Sheffield with the Institute of Acoustics. Topics will include: architecture, building and environmental acoustics; music and music space soundscape sound quality; auditory system noise and vibration measurement and evaluation; environmental psychology and physiology; built environmental design including visual, heat and indoor air environments. More information can be found at: http://www.ioa.org.uk/events/event.asp?id=104
7) The Conference of the Australian Acoustical Society Breaking New Ground, Holiday Inn, Surfers Paradise, Queensland Australia, November 2-4 2011.
Conference of the Australian Acoustical Society Breaking New Ground November 2-4 2011. The Australian Acoustical Society Conference 2011 will be held between the 2nd and 4th of November 2011 at the Holiday Inn in the heart of Australia’s favorite holiday destination on the Gold Coast, Queensland. The conference theme, Breaking New Ground, is based on the recent boom in large infrastructure projects. Major infrastructure for transportation, industry and mining present challenges in noise and vibration, whether these are in assessment, modeling or mitigation or in the need to provide appropriate legislative and regulatory frameworks. This conference will break new ground as delegates review recent developments and address the challenges and opportunities presented by the construction and operational phases of such infrastructure. Other major topics for the Conference will include Underwater Acoustics and Architectural and Building Acoustics. However, papers from all areas of acoustics are welcomed. For further details for the conference theme and other topics of interest for the Conference of the Australian Acoustical Society go to: http://www.mech.uq.edu.au/acoustics2011/Overview.htm
ITEM 4. NATIONAL ACOUSTICAL LABORATORIES AND RESEARCH ACTIVITIES:
1) Studies on human echolocation in the Research and Transfer Center on Acoustics (CINTRA), Cordoba, Argentina.
The main aim of one of the interdisciplinary research lines from the CINTRA ―National Technological University(UTN) and Associated Unity of the National Scientific and Technical Research Council (CONICET) ― is the study of human echolocation at short distances. This ability may be used daily by human beings, even without being conscious of it. It turns out to be crucial for the achievement of the efficient independent mobility of blind persons, an aspect that is severely affected by blindness. It implies the use of self-generated sounds (original or direct signal) with the specific purpose of obtaining auditory information (reflected signals) to locate and recognize unseen silent objects. According to the new cognitive and ecological paradigms in perception, it is believed that the primary function of the auditory system is to determinate, i.e., to localize and recognize, the characteristics of the sound source through the sounds emitted by it. Within this context, it has been very recently argued that echolocation is a variant of that general process.
Two recently established scientific paradigms have specially enriched the study of this amazing ability: the sensory-motor contingency theory and the sensory substitution perspective. The first approach claims that the perceptual and motor systems are coupled processes that demand a thoroughly unified treatment. The second approach considers that, for example, vision loss does not mean loss of the ability to see since it is possible to see with the ears or the skin. The central idea is that the information usually captured by vision may instead be captured by touch or audition, on account of brain plasticity. Our research group on human echolocation was formed more than 25 years ago, and it is led by Dr. Claudia Arias. The research groups are composed of the following interdisciplinary staff members: Mercedes Hug (psychologist), Aldo Ortiz Skarp (systems analyst), Fernando Bermejo (psychologist), Nicolas Venturelli (philosopher), Diana Rabinovich (philosopher), Facundo Barrera (advanced student of electronic engineering), Valentin Lunati (advanced student of electronic engineering) and Carolina Nassif (advanced student of psychology).
Currently, three projects ―granted by CONICET, the National University of Cordoba (UNC) and the UTN are being carried out whose main aims are: To characterize head movements in participants with and without sensory handicap (blindness and unilateral deafness) in three auditory tests without visual cues: direct and reflected sounds, localization tests and an echolocation test of real silent objects; To determine developmental aspects of sound localization and related auditory phenomena in sighted and blind infants and their possible implications on the human echolocation ability (PhD project finished); To characterize the structuring processes of auditory space perception without visual cues in adults with and without visual impairment equipped with natural and artificial sensory substitution systems or assisted with specific computer games (current PhD project).
Contact e-mail address: email@example.com
2) The research project Human response to vibration in residential environment the University of Salford, UK.
The research project Human response to vibration in residential environment funded by the UK Department for Environment, Food and Rural Affairs (DEFRA) will reach completion in March 2011. The research was carried out by the University of Salford, UK with guidance from an expert panel including Colin Grimwood (Bureau Veritas), Henk Miedema and Sabine Janssen (TNO), Richard Perkins, (Parsons Brinckerhoff), Colin Stanworth (BSI), and Rupert Thornely-Taylor (Rupert Taylor Ltd). This work will be of interest to acoustical consultants and environmental health officers involved in the assessment of vibration complaints, as well as to planners and practitioners involved in the design of buildings. The objective of the study has been to demonstrate a robust relationship between vibration exposure and human response (i.e. annoyance levels), to ultimately provide a reliable basis for the development of standards and guidance when assessing vibration in residential buildings. The project has considered vibration sources that are outside the control of residents, such as construction, road and rail activities. In addition, noise is also a consideration as it is a frequent companion to vibration exposure. The protocol involved the measurement of vibration outside and inside individual residences and a social study questionnaire based on face-to-face interviews with householders, with a final total of approximately 1500 case studies obtained. This project completes a total of seven years research funded by DEFRA aimed at developing exposure-response relationships to vibration and noise in residential environments. The final report will consist of a short project report and a number of technical reports. The detailed technical reports will address the measurement of vibration exposure, the measurement of response, the calculation of vibration exposure, the measurement and calculation of noise exposure, the results and analysis of response data, and the determination and analysis of exposure-response relationship. The report is expected to be published in Summer 2011. [Work funded by the Department for Environment, Food and Rural Affairs (DEFRA) UK].
3)Aeroacoustics Research at the University of Adelaide, Australia.
The University of Adelaide has recently been developing a research program in aeroacoustics/flow induced noise. There are several experimental and numerical projects underway, funded by the Australian Research Council, the Australian Defense Science and Technology Organisation (DSTO) and Industry. A summary of these projects is given below.
The Mechanics of Quiet Airfoils: This is a fundamental investigation of how turbulent flow creates noise at the trailing edge of an airfoil. Experiments, involving a range of airfoil shapes, are being conducted in the University anechoic wind tunnel.
Recent results are providing important insight and new results concerning the production of trailing edge noise at low-to-moderate Reynolds number. The project is also developing numerical methods to predict trailing edge noise and will use these models in an aeroacoustic shape optimisation methodology. RANS based Statistical Noise Method (RSNM). This project is developing a new prediction methodology for airfoil and bluff body sound generation. Its aim is to have an accurate yet efficient method of sound generation based on RANS CFD solutions to make aeroacoustic problems tractable by industry and designers.
Understanding and predicting submarine hydrofoil noise. This is a collaborative project between Deep Blue Tech (DBT), the Defense Science and Technology Organisation (DSTO) and the University of Adelaide. Its aim is to develop a much better understanding of hydrofoil self noise through experiment and numerical simulation.
Flow-Induced-Noise Generated by Wall-Mounted Cylinders. This fundamental project (supported by DSTO) is looking at the flow and noise generated by wall mounted cylinders. Such situations occur on the hull of submarines, fuselage of aircraft and external surfaces of automobiles.
The effect of a detached plate on the sound generated by a bluff body in cross flow. This project is investigating, by numerical direct numerical simulation, the effect of wake interference on the production of sound by bluff bodies. Results show that noise can be reduced or intensified, depending on the type of wake interference. Work is progressing towards developing an optimal size and position of a detached plate to achieve minimum radiated noise. The person leading this work is Dr Con Doolan firstname.lastname@example.org. Other researchers that are part of the team include Dr Laura Brooks, Professor Colin Hansen, Dr Danielle Moreau and Associate Prof Anthony Zander plus a number of outstanding graduate students.
4) Vibration Analysis in Light Synchrotrond.
MAX-lab is a national laboratory operated jointly by the Swedish Research Council and Lund University. Nowadays, the MAX project consists of three facilities, (three storage rings): MAX-I, MAX-II, MAX-III and one electron pre-accelerator called MAX-Injector. New methods are needed in order to improve analysis of different materials, and so is a new storage ring due to improved nanotechnology. Thus, MAX IV will be 100 times more efficient than already existing synchrotron radiation facilities becoming a world leading facility for studies of particles at a nano-level by using synchrotron light.
Division of Acoustics Engineering, Lund University, John Ericsson vag 1, 22100 Lund, Sweden, e-mail:
5) NWAA Labs Seattle, Washington.
NWAA Labs is an independent laboratory providing uniform loudspeaker testing and material testing to the audio, acoustics, and construction industries. NWAA Labs has the ability to do MACH Testing and high SPL testing of these items to meet or exceed ISO and ASTM standards. Ron Sauro, the president of NWAA Labs, recently signed a four-year lease with the Satsop Development Park for his part of the reactor building. At a height equal to 16 stories – several of them underground the reactor building is a somewhat dwarfed by the cooling towers but is an excellent place to conduct experiments of all kinds. Sauro company, NWAA Labs, tests the sound absorption and transmission properties of building materials such as windows, doors and acoustical materials used in wall structures, ceilings and floors. He also tests sound equipment such as speakers to see how they project sound. Inside the reactor building Sauro has created a temporary, proof of concept two-room acoustical reverberation and transmission loss suite that is thought to be one of the largest in the world. No one actually works in the rooms. The materials are set in place for testing and later removed. Testing is monitored from a nearby control room. The send room or small reverberation chamber is 23 and half feet high by 35 feet by 30 feet with walls built of 1-foot thick concrete. The receive room also known as the main reverberation chamber, is 17 and half feet high by 42 feet by 35 feet, surrounded by walls that are 3-feet thick.
Sauro is presently creating another test room this one an anechoic chamber. Once that is complete, Sauro has plans for building his real reverberation sound lab while he continues to use the temporary proof of concept lab to test materials. The real lab will be 28 feet by 45 feet by 80 feet and be able to test curtain walls used as sound breaks in skyscrapers.
Contact information: Ron Sauro: email@example.com; http://www.nwaalabs.com/
ITEM 5. NEW BOOK ANNOUNCEMENTS:
1) Command Generation for Dynamic Systems by By William Singhose, Warren Seering
Perfect-bound Paperback: 159 pages
Publisher: William Singhose (January 17, 2011)
Price: 52.55 USD
Command Generation for Dynamic Systems presents techniques for moving machines very rapidly. The main focus is on intelligently designing the reference command that is used to drive the system. Numerous example systems, such as cranes, robots, and satellites are discussed.
2) Hilbert Transform Applications in Mechanical Vibration by Michael Feldman
Hardcover: 304 pages
Publisher: Wiley (May 2011)
Price: 135.00 USD
Hilbert Transform Applications in Mechanical Vibration addresses recent advances in theory and applications of the Hilbert transform to vibration engineering, enabling laboratory dynamic tests to be performed more rapidly and accurately. The author integrates important pioneering developments in signal processing and mathematical models with typical properties of mechanical dynamic constructions such as resonance, nonlinear stiffness and damping. A comprehensive account of the main applications is provided, covering dynamic testing and the extraction of the modal parameters of nonlinear vibration systems, including the initial elastic and damping force characteristics. This unique merger of technical properties and digital signal processing allows the instant solution of a variety of engineering problems and the in-depth exploration of the physics of vibration by analysis, identification and simulation. This book will appeal to both professionals and students working in mechanical, aerospace, and civil engineering, as well as naval architecture, biomechanics, robotics, and mechatronics.
3) Introduction to Finite Element Vibration Analysis. Second Edition by Maurice Petyt.
Hardcover: 516 pages
Publisher: Cambridge University Press; second edition (September 2010)
Price: 112.00 USD
Introduction to Finite Element Vibration Analysis Second Edition by Maurice Petyt presents an introduction to the mathematical basis of finite element analysis as applied to vibrating systems. This second edition includes information on the many developments that have taken place over the last 20 years. Existing chapters have been expanded, where necessary, and three new chapters have been included that discuss the vibration of shells and multilayered elements and provide an introduction to the hierarchical finite element method. This is an introduction to the mathematical basis of finite element analysis as applied to vibrating systems. Finite element analysis is a technique that is very important in modeling the response of structures to dynamic loads. Although this book assumes no previous knowledge of finite element methods, those who do have knowledge will still find the book to be useful. It can be utilized by aeronautical, civil, mechanical, and structural engineers as well as naval architects. This second edition includes information on the many developments that have taken place over the last twenty years. Existing chapters have been expanded where necessary, and three new chapters have been included that discuss the vibration of shells and multi-layered elements and provide an introduction to the hierarchical finite element method.
ITEM 6. RECENT DOCTORAL THESES:
1) Theoretical and experimental modal analysis of nonlinear vibrating structures using nonlinear normal modes;
Maxime Peeters, Ir.
Structural Dynamics Research Group
Aerospace and Mechanical Engineering Department
University of Liege
Chemin des chevreuils, 1
Theoretical and experimental modal analysis, i.e., the computation of vibration modes from a mathematical model and from experimental data, respectively, is quite sophisticated and advanced in linear structural dynamics. However, nonlinearity is a frequent occurrence in real-world engineering structures, and the existing linear methodologies fail dramatically in the presence of nonlinear dynamical phenomena. Therefore, the present thesis focuses on the development of a practical nonlinear analog of modal analysis for properly accounting for nonlinearity in mechanical systems. The concept of nonlinear normal mode (NNM) provides solid mathematical and theoretical foundations for a rigorous, yet understandable by the practicing engineer, analysis of nonlinear dynamical behaviors. In this context, a useful framework for nonlinear modal analysis of vibrating structures, which includes the computation of NNMs from finite element models and their identification from experimental data, is proposed in this dissertation. In view of the still limited use of NNMs in structural dynamics, special attention is devoted to progress toward a practical tool that has the potential to deal with large-scale, real-world structures. Targeting an effective and exact computation of NNMs, even in strongly nonlinear regimes of motion, one original contribution of this work is to resort to numerical methods. An algorithm combining a shooting procedure and the so-called pseudo-arclength continuation method is developed. On the other hand, a nonlinear extension of phase resonance testing (also known as force appropriation) is introduced for the experimental identification of NNMs, which is another innovative aspect of the doctoral thesis. In particular, the phase lag quadrature criterion, which is used for linear experimental modal analysis is generalized in the presence of nonlinear dynamical behavior. Academic examples are first considered to illustrate, in a simple manner, that the proposed methods form an effective and adequate framework for nonlinear modal analysis. Furthermore, more realistic structures, including a full-scale aircraft, are studied to demonstrate the potential applicability of the approach to large-scale, real-life applications.
2) Tuning methodology of nonlinear vibration absorbers coupled to nonlinear mechanical systems.
Regis Viguie, Ir.
Structural Dynamics Research Group
Aerospace and Mechanical Engineering Department
University of Liege
Chemin des chevreuils, 1
A large body of literature exists regarding linear and nonlinear dynamic absorbers, but the vast majority of it deals with linear primary structures. However, nonlinearity is a frequency occurrence in engineering applications. Therefore, the present thesis focuses on the mitigation of vibrations of nonlinear primary systems using nonlinear dynamic absorbers. Because most existing contributions about their design rely on optimization and sensitivity analysis procedures, which are computationally demanding, or on analytic methods, which may be limited to small-amplitude motions, this thesis sets the emphasis on a tuning procedure of nonlinear vibration absorbers that can be computationally tractable and treat strongly nonlinear regimes of motion. The proposed methodology is a two-step procedure relying on a frequency-energy based approach followed by a bifurcation analysis. The first step, carried out in the free vibration case, imposes the absorber to possess a qualitatively similar dependence on energy as the primary system. This gives rise to an optimal nonlinear functional form and an initial set of absorber parameters. Based upon these initial results, the second step, carried out in the forced vibration case, exploits the relevant information contained within the nonlinear frequency response functions, namely, the bifurcation points. Their tracking in parameter space enables the adjustment of the design parameter values to reach a suitable tuning of the absorber. The use of the resulting integrated tuning methodology on nonlinear vibration absorbers coupled to systems with nonlinear damping is then investigated. The objective lies in determining an appropriate functional form for the absorber so that the limit cycle oscillation suppression is maximized. Finally, the proposed tuning methodology of nonlinear vibration absorbers may impose the use of complicated nonlinear functional forms whose practical realization, using mechanical elements, may be difficult. In this context, an electro-mechanical nonlinear vibration absorber relying on piezoelectric shunting possesses attractive features as various functional forms for the absorber nonlinearity can be achieved through proper circuit design. The foundation of this new approach is laid down and the perspectives are discussed.
3) Experimental Modal Analysis using Blind Source Separation Techniques.
Dynamic Research Group
Aerospace and Mechanical Engineering Department
University of Liege
Chemin des chevreuils, 1
This dissertation deals with dynamics of engineering structures and principally discusses the identification of the modal parameters (i.e., natural frequencies, damping ratios and vibration modes) using output-only information, the excitation sources being considered as unknown and immeasurable. To solve these kinds of problems, a quite large selection of techniques is available in the scientific literature, each of them possessing its own features, advantages and limitations. One common limitation of most of the methods concerns the post-processing procedures that have proved to be delicate and time consuming in some cases, and usually require good user expertise. The constant concern of this work is thus the simplification of the result interpretation in order to minimize the influence of this ungovernable parameter. A new modal parameter estimation approach is developed in this work. The proposed methodology is based on the so-called Blind Source Separation techniques that aim at reducing large data set to reveal its essential structure. The theoretical developments demonstrate a one-to-one relationship between the so-called mixing matrix and the vibration modes. Two separation algorithms, namely the Independent Component Analysis and the Second-Order Blind Identification, are considered. Their performances are compared, and, due to intrinsic features, one of them is finally identified as more suitable for modal identification problems. For the purpose of comparison, numerous academic case studies are considered to evaluate the influence of parameters such as damping, noise and nondeterministic excitations. Finally, realistic examples dealing with a large number of active modes, typical impact hammer modal testing and operational testing conditions, are studied to demonstrate the applicability of the proposed methodology for practical applications.
ITEM 7. HONOURS AND AWARDS:
1) INCE/USA Announces the Leo Beranek Student Medal for Excellence in the Study of Noise Control. This special Medal was established by the Board of Directors of INCE/USA on October 24, 2010 to recognize excellence in the study of noise-control by undergraduate and graduate students at academic institutions in North America that have courses in, or related to, noise-control engineering including practical applications.
2) Matthew A. Davies, (1) Bank of America Teaching Award Finalist;(2) Elected Fellow of the International Academy for Production Engineering Research;
Matthew A. Davies, Ph.D. | Associate Professor of Mechanical Engineering
UNC Charlotte | 232 Duke Centennial Hall
9201 University City Blvd. | Charlotte, NC 28223
(1) Bank of America Teaching Award Finalist
(2) Elected Fellow of the International Academy for Production Engineering Research
(3) Recent Grants
a. High speed micro-milling of optical devices for infra-red beam shaping and imaging, II-VI Foundation, http://ii-vifoundation.com/
b. Fabrication of Multi-scale Optics through Free-Form Micromachining: Hierarchical Manufacturing across Seven Orders of Magnitude
3) Marek Pawelczyk has been appointed as \"Honorary Ambassador of Congresses for Poland\". Marek Pawelczyk:
ITEM 8. RESEARCH POSITION AVAILABLE:
A Post-Doctoral research fellow in acoustics/vibrations, The School of Mechanical Engineering, the University of Adelaide, Australia.
The School of Mechanical Engineering is currently seeking a Research Associate to participate in an Australian Research Council funded linkage project with the company Trackside Intelligence Pty Ltd (TrackIQ), to further develop their trackside system for monitoring the condition of wheel bearings on railway rolling stock. The current system uses an advanced microphone array, ancillary sensors and sophisticated signal processing to diagnose bearing faults in freight trains as they pass a monitoring station at normal operational speed. Other monitoring products use arrays of load cells and accelerometers to detect wheel defects in underway rail vehicles. TrackIQ has more than 100 systems installed on railway lines in nine countries.This ARC funded project involves laboratory tests, field trials in Australia & overseas, and the development of analytical models to underpin the further development of the technology and its extension to other, more complex types of operational rail vehicles, with goals of reduced maintenance costs and increased operational safety. The project has the support of large Australian and international rail transport companies.
We are seeking a Research Associate with a PhD in acoustics, vibration, signal processing or a related discipline to participate in this project, for its duration of three years. A skills mix spanning use of multi-channel measurement systems and advanced analytical methods, is required. Salary: (Research Associate, Level B) $76,157 per annum, plus attractive superannuation benefits. Further information, including selection criteria may be obtained from
Dr. Carl Howard. The position is expected to commence in May or June, 2011.
SCHOOL OF MECHANICAL ENGINEERING
THE UNIVERSITY OF ADELAIDE SA 5005
TELEPHONE +61 8 8303 5460
FACSIMILE +61 8 8303 4367
ITEM 9. INDUSTRIAL NEWS.
1)Marshall Day Acoustics releases the North American version of INSUL v6.4.
Marshall Day Acoustics has released the North American version of INSUL v6.4. The new version includes a number of developments that are particularly interesting for North American acoustics professionals. The new software includes an impact sound for light weight timber floors, sandwich panels with polystyrene or rockwool core panels, porous material TL, improved profiled steel and aluminum panel predictions.
A trial version of INSUL 6.4 can be downloaded from the following hyperlink: www.navcon.com/insulsoftware.htm<http://www.navcon.com/insulsoftware.htm> The current download will automatically activate a INSUL trial version through February 13, 2011. After that please send an email to firstname.lastname@example.org<mailto:email@example.com> requesting a trial license file.
Navcon Engineering Network - Noise & Vibration Consultants
Sender: Hans Forschner, Sr. Acoustical Engineer
Address 701 West Las Palmas Dr., Fullerton, CA 92835
Web Site: www.navcon.com<blocked::http://www.navcon.com/>
2) BYD (Build Your Dreams) - Chinese automotive manufacturer has chosen IAC to provide a range of state of the art anechoic chambers and quiet rooms for testing new vehicles prior to production. The project is being co-ordinate by the UK and Chinese offices.
3)IAC Colpro have acquired Sound Attenuators Australia and Acoustic Systems - IAC Colpro acquired both companies in late 2010 extending their range of available markets and building on the already successful business in the mining sector. Both Sound Attenuators Australia and Acoustic Systems were providers of noise control solutions for building services.
4) IAC UK has Provided Head of Stand Cabins to British Airways (BA) -IAC product, the Fli-Pod has received compliments from praise BA as a cost effective solution to improving the efficiency of ground staff working with in and outbound aircraft. The Fli-Pod is a bespoke acoustically controlled environment, meaning that ground staff can work in peace and tranquility whist remaining very close to the aircraft, saving time and money.
Additional information can also be obtained from: http://www.industrialacoustics.com/uk/news/index.asp
ITEM 10. NEW PATENT SPECIFICATION.
An Invention - United States Patent Nr.:7261182 / 2007 and European Patent Nr.: 1506541 /2010: Roundffusor1 (R1) - the complete acoustical material R1 is an active and clean sound diffuser (from around 180-250Hz to 20.000 Hz) & adaptable low frequency absorber (5 - 250 Hz).The present invention relates to an acoustical diffuser device, said apparatus comprising two lateral rigid supports, mounted to the inside of the said diffuser which lateral supports are received, like a drawer , by two wooden rails, section \"T\". The two wooden rails \"T\" are simply mounted on the wall surface with screws or nails. The main diffuser body with his two drivers is mounted just like a drawer toward the two rails T. The main body is composed from three basically 3D shapes. Each fourth diffusers, displays together a new 3D shapes at their nearest point. The angle between each 3D shape, including the new common shape and his neighbor shapes is the same. From the total surface of each diffuser there is more than 90 % diffusing surface. Except the wooden rails, section \"T\", the complex diffuser body and his lateral supports are fabricated from hard impact polystyrene or any material suitable for the device geometry using vacuum thermoforming, injection molding, blow molding facilities or any other suitable way, keeping the same device geometry, the lateral supports being added with adhesives or produced from the same material as one piece with the diffuser device main body.
For further information please contact Mr. Zainea Liviu: firstname.lastname@example.org or visit: www.zainea.com
ITEM 11. IIAV: Membership Application Form for the INTERNATIONAL INSTITUTE OF ACOUSTICS AND VIBRATION (IIAV)
President: Hans Boden, [Sweden]
Vice Presidents: Marek Pawelczyk,[Poland]
Secretary: Semyung Wang, [South Korea]
Treasurer: Zhuang Li, [United States of America]
Executive Director: Malcolm Crocker, [United States of America].
The International Institute of Acoustics and Vibration (IIAV) incorporated in June 1995, is a non-profit scientific society whose membership is open to qualified individuals in all countries.
PURPOSE The Institute has been created to advance the science of acoustics and vibration by creating an international scientific society that is responsive to the needs of scientists and engineers in all countries whose primary interests are in the fields of acoustics and vibration. The Institute shall cooperate with scientific societies in all countries and with other international organizations with the aim of increasing information exchange by sponsoring, cosponsoring or supporting seminars, workshops, congresses and publishing or providing journals or other publications. The Institute will provide an electronic International Sound and Vibration Digest (ISVD) and a paper refereed journal (the International Journal of Acoustics and Vibration) for all members as part of their dues.
MEMBERSHIP There are six classifications of membership in the Institute including: Fellow, Member, Associate, Student Member, Emeritus Member, and Honorary Fellow. All memberships entitle a member to receive the publications of the Institute and to attend Institute meetings. Those entitled to vote at Institute meetings are restricted to Fellows, Members and Emeritus Members. Fellows, Members, Emeritus Members and Honorary Fellows are eligible to hold office. Membership as Member is open to all those who have at least a baccalaureate degree or its equivalent from an accredited institution and who are employed or have been employed in an activity related to acoustics and/or
vibration. Membership as Associate is open to all persons who wish to support and promote the activities of the Institute, but who do not meet the criteria for membership as Member.
DUES The membership dues are $80 per year. Membership dues for those from some countries will be at a lower rate. Members will begin receiving the electronic ISVD and the journal immediately on joining the Institute.
OFFICERS AND DIRECTORS The officers of the Institute are the President, the President-Elect, the Immediate Past President, the Vice President for Professional Relations, the Vice President for Communications, the Secretary and Treasurer. The President, President-Elect and Immediate Past President hold office for two years. The other officers hold office for four years. The directors of the Institute hold office for four years. The officers and directors are elected by the members of the Institute.
COOPERATING SCIENTIFIC SOCIETIES The Institute recognizes that many scientific societies with interests in acoustics and/or vibration exist in different countries. It is the purpose of the Institute to supplement their activities and to cooperate with them for the good of scientists and engineers throughout the world. To that end, existing scientific societies will be encouraged to become affiliated with the Institute as cooperating member societies.
IIAV MEMBERSHIP APPLICATION FORM
If you are interested in joining the IIAV, please fill in the form and return It by fax or e-mail (see following).
Malcolm J. Crocker
Mechanical Engineering Department
270 Ross Hall
Auburn, AL 36849, USA
Application form: ( ) Member ( ) Associate
1) Name: _____________________________________________________
2) Address: ____________________________________________________________
Fax: _____________________ E-mail: ____________________________
3) Degrees (Institutions and dates):
4) Employment (with dates):
5) Signature & Date: _______________________________________________________