Sound Characterization through Intensity of Acoustic Radiation Measurement: A Study of Persian Musical Instruments

Lamberto Tronchin; Massimiliano Manfren; Vincenzo Vodola

doi:10.3390/app10020633

Sound Characterization through Intensity of Acoustic Radiation Measurement: A Study of Persian Musical Instruments

Applied Sciences ◽

10.3390/app10020633 ◽

2020 ◽

Vol 10 (2) ◽

pp. 633 ◽

Cited By ~ 7

Author(s):

Lamberto Tronchin ◽

Massimiliano Manfren ◽

Vincenzo Vodola

Keyword(s):

Modal Analysis ◽

Sound Propagation ◽

Acoustic Radiation ◽

Mechanical Vibration ◽

Sound Radiation ◽

The United States ◽

Acoustic Parameter ◽

Musical Instruments ◽

Weak Correlation ◽

Mechanical Vibrations

The physics of musical instruments often uses modal analysis as one of the most important methods for describing the behavior of sound chests and their acoustic radiation. However, some studies conducted in Europe (Wogram), Japan (Suzuki) and the United States (Giordano) underlined a very weak correlation between sound radiation and modal analysis. This mismatch required further research. The acoustic parameter intensity of acoustic radiation (IAR) is highly related to the mechanical vibration of the sound source. IAR was able to quantify the sound efficiency of musical instruments, and to relate sound radiation with modal analysis. This paper investigates IAR measured on three Persian stringed musical Instruments, namely the thar, si-thar and santoor. The analysis contributes to the knowledge of stringed musical instruments and sound propagation, since IAR is capable of linking the mechanical vibrations of soundboards with the sound generation of the musical instruments. The IAR results coming from the modal analysis carried out during the study of the instruments are reported herein.

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Modal Analysis and Rotor-Dynamics of an Interior Permanent Magnet Synchronous Motor: An Experimental and Theoretical Study

Applied Sciences ◽

10.3390/app10175881 ◽

2020 ◽

Vol 10 (17) ◽

pp. 5881

Author(s):

Selma Čorović ◽

Damijan Miljavec

Keyword(s):

Modal Analysis ◽

Permanent Magnet ◽

Permanent Magnets ◽

Natural Frequencies ◽

Permanent Magnet Synchronous Motor ◽

Mechanical Vibration ◽

Mechanical Vibrations ◽

Wide Range ◽

Interior Permanent Magnet ◽

Interior Permanent Magnets

This paper investigates mechanical vibrations of an interior permanent magnet (IPM) synchronous electrical motor designed for a wide range of speeds by virtue of the modal and rotordynamic theory. Mechanical vibrations of the case study IPM motor components were detected and analyzed via numerical, analytical and experimental investigation. First, a finite element-based model of the stator assembly including windings was set up and validated with experimental and analytical results. Second, the influence of the presence of the motor housing on the natural frequencies of the stator and windings was investigated by virtue of numerical modal analysis. The experimental and numerical modal analyses were further carried out on the IPM rotor configuration. The results show that the natural frequencies of the IPM rotor increase due to the presence of the magnets. Finally, detailed numerical rotordynamic analysis was performed in order to investigate the most critical speeds of the IPM rotor with bearings. Based on the obtained results, the key parameters related to mechanical vibrations response phenomena, which are important when designing electrical motors with interior permanent magnets, are provided. The main findings reported here can be used for experimental and theoretical mechanical vibration analysis of other types of rotating electrical machines.

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The Carabattola—Vibroacoustical Analysis and Intensity of Acoustic Radiation (IAR)

Applied Sciences ◽

10.3390/app10020641 ◽

2020 ◽

Vol 10 (2) ◽

pp. 641 ◽

Cited By ~ 6

Author(s):

Lamberto Tronchin ◽

Massimiliano Manfren ◽

Vincenzo Vodola

Keyword(s):

Twentieth Century ◽

Modal Analysis ◽

Acoustic Analysis ◽

Acoustic Radiation ◽

Vibrational Analysis ◽

Musical Instruments ◽

Experimental Part ◽

Percussion Instruments ◽

Acoustic Analyses ◽

Romagna Area

Among the studies of musical instruments, one important, sometime underestimated discipline, is represented by ethnomusicology. The acoustic analyses on ethnic musical instruments (M.I.) are much more infrequent if compared to those on classical M.I. This article deals with the vibro-acoustic analysis on one of the most unknown ethnic, Italian M.I., i.e., the carabattola (also called battola), which used to be played in Italy until the late 1960s during the Holy Thursday before Easter. The study includes modal analysis and Intensity of Acoustic Radiation measured on an original carabattola, which was played in the Romagna area until the early twentieth century. After a brief overview about the theory of acoustic and vibrational analysis on musical instruments, the Intensity of acoustic radiation and its correlation with modal analysis are recalled, based on previous studies. In the experimental part of the article, the measurements conducted on the carabattola are described. Afterwards, the results obtained both from modal analysis and IAR measurements are analyzed and compared with other measurements previously conducted on musical (particularly percussion) instruments and commented.

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The Use of Modan 3D in Experimental Modal Analysis

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.486.36 ◽

2013 ◽

Vol 486 ◽

pp. 36-41 ◽

Cited By ~ 3

Author(s):

Róbert Huňady ◽

František Trebuňa ◽

Martin Hagara ◽

Martin Schrötter

Keyword(s):

Modal Analysis ◽

Vibration Analysis ◽

High Speed ◽

Mechanical Vibration ◽

Steel Sample ◽

Experimental Modal Analysis ◽

Image Correlation ◽

Optical Methods ◽

Mode Shapes ◽

Vibration Modes

Experimental modal analysis is a relatively young part of dynamics, which deals with the vibration modes identification of machines or their parts. Its development has started since the beginning of the eighties, when the computers hardware equipment has improved and the fast Fourier transform (FFT) could be used for the results determination. Nowadays it provides an uncountable set of vibration analysis possibilities starting with conventional contact transducers of acceleration and ending with modern noncontact optical methods. In this contribution we mention the use of high-speed digital image correlation by experimental determination of mode shapes and modal frequencies. The aim of our work is to create a program application called Modan 3D enabling the performing of experimental modal analysis and operational modal analysis. In this paper the experimental modal analysis of a thin steel sample performed with Q-450 Dantec Dynamics is described. In Modan 3D the experiment data were processed and the vibration modes were determined. The reached results were verified by PULSE modulus specialized for mechanical vibration analysis.

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Application of FEM Modal Analysis to the Estimation of Sound Radiation Power.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C ◽

10.1299/kikaic.63.3824 ◽

1997 ◽

Vol 63 (615) ◽

pp. 3824-3831 ◽

Cited By ~ 1

Author(s):

Yoshihito KAGAWA ◽

Iwao HAYASHI ◽

Nobuyuki IWATSUKI

Keyword(s):

Modal Analysis ◽

Radiation Power ◽

Sound Radiation ◽

Sound Radiation Power

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Active Control of Vibration and Noise Radiation from Fluid-Loaded Cylinder using Active Constrained Layer Damping

Journal of Vibration and Control ◽

10.1177/1077546029206 ◽

2002 ◽

Vol 8 (6) ◽

pp. 877-902 ◽

Cited By ~ 12

Author(s):

W. Laplante ◽

T. Chen ◽

A. Baz ◽

W. Sheilds

Keyword(s):

Finite Element ◽

Finite Element Model ◽

Acoustic Radiation ◽

Sound Radiation ◽

Element Model ◽

Water Tank ◽

Constrained Layer Damping ◽

Active Constrained Layer Damping ◽

Active Constrained Layer ◽

Surrounding Fluid

Vibration and sound radiation from fluid-loaded cylindrical shells are controlled using patches of Active Constrained Layer Damping (ACLD). The performance and the enhanced damping characteristics via reduced vibrations and sound radiation in the surrounding fluid is demonstrated both theoretically and experimentally. A prime motivation for this work is the potential wide applications in submarines and torpedoes where acoustic stealth is critical to the effectiveness of missions. A finite element model is also developed to predict the vibration and the acoustic radiation in the surrounding fluid of the ACLD-treated cylinders. The developed model is used to study the effectiveness of the control and placement strategies of the ACLD in controlling the fluid-structure interactions. A water tank is constructed that incorporates test cylinders treated with two ACLD patches placed for targeting specific vibration modes. Using this arrangement, the effectiveness of different control strategies is studied when the submerged cylinders are subjected to internal excitation, and the radiated sound pressure level in the water is observed. Comparisons are made between the experimental results and the theoretical predictions to validate the finite element model.

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Mediating role of resilience between successful aging and acculturation among older Korean immigrants In the United States

Advances in Social Sciences Research Journal ◽

10.14738/assrj.75.8185 ◽

2020 ◽

Vol 7 (5) ◽

pp. 117-133

Author(s):

Jaewon Lee

Keyword(s):

Los Angeles ◽

Acculturative Stress ◽

Successful Aging ◽

Healthy Aging ◽

The United States ◽

Korean Immigrants ◽

Future Research ◽

Weak Correlation ◽

Cross Sectional Survey ◽

Older Korean Immigrants

Background: This study was to investigate how acculturative stress affects older Korean immigrants' successful aging and whether resilience can play a mediator's role to the sample population's successful aging or not. The research design was a cross-sectional survey using three valid and reliable scales such as Successful Aging Scale, Acculturative Stress Scale, and Resilience Scale. A research shows that there is no or minimum correlation between acculturative stress and successful aging (Choi & Thomas, 2009). However, it was hypothesized that although there was a weak correlation between acculturative stress and successful aging, once the resilience involved as a mediator, the correlation would be stronger. Methods: The study was designed as a self-administered survey research using the scales mentioned above. One hundred and two (N=102) older Koreans who currently enrolled in Adult Health Care Centers in Los Angeles, CA, participated in this study. Multiple Regression, Correlation, ANOVA, and t-test was administered to analyze the collected data. Results: The results indicated that there was a positive but weak correlation between acculturative stress and the sample population's successful aging rate (r = .252, p<.05). Interestingly, when resilience intervened as a mediator, the correlation between acculturation and successful aging was increased to (r = .622, p<.05). Therefore, the study discovered that the resilience was able to play a mediator's role between acculturative stress and successful aging among the older Korean immigrants. Implications: The findings can be directed to social work researchers and practitioners to help educate the ethnic older adults in the community on the social and behavioral importance of the positive aspects of aging such as successful aging and healthy aging to increase the chance of community member's longevity. Future research will include other ethnic and immigrant older populations in the community to show internal and external validity of the study related to successful aging, acculturative stress, and resilience.

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DYNAMIC RESEARCH OF SOLAR CELLS / DINAMINIS SAULĖS ELEMENTO TYRIMAS

Mokslas - Lietuvos ateitis ◽

10.3846/mla.2016.984 ◽

2017 ◽

Vol 8 (6) ◽

pp. 549-522

Author(s):

Vytautas Makarskas ◽

Mindaugas Jurevičius ◽

Artūras Kilikevičius

Keyword(s):

Renewable Energy ◽

Solar Cells ◽

Solar Cell ◽

Modal Analysis ◽

Cell Structure ◽

Mechanical Vibrations ◽

Maintenance Costs ◽

Solar Cell Structure ◽

Cell Stability ◽

Renewable Energy Generation

Solar cells are one of the most popular renewable energy generation technologies, because they are reliable, low operating and maintenance costs, to conclude without any moving parts and is a boundless source of energy. In any solar cell can avoid mechanical vibrations, which may produce the solar cell glass, damage to the inner structure. In order to determine the influence of mechanical vibrations of the solar cell structure was carried out theoretical and experimental modal analysis. The study found dangerous solar cell frequencies and their deformation and optimize the method of attachment which provides a better solar cell stability. Saulės elementai – vieni populiariausių atsinaujinančių energijos gavybos technologijų, nes jie patikimi, jų mažos eksploatavimo ir priežiūros išlaidos, šie elementai sudaryti be jokių judančių dalių ir yra beribis energijos šaltinis. Bet saulės elementas neišvengia mechaninių virpesių, kurie gali įskelti saulės elemento stiklą, pažeisti vidinę konstrukciją. Siekiant nustatyti mechaninių virpesių įtaką saulės elemento konstrukcijai, buvo atliktos teorinės ir eksperimentinės modalinės analizės. Tyrime buvo rasti pavojingi saulės elemento dažniai ir jų deformacijos, rastas optimalus tvirtinimo būdas, kuris suteikia geresnį saulės elemento stabilumą.

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Research on the Insulation Performance of Sound-Isolating and Decoupled Tiles

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.457-458.703 ◽

2013 ◽

Vol 457-458 ◽

pp. 703-706 ◽

Cited By ~ 1

Author(s):

De Jin Qian ◽

Xue Ren Wang ◽

Xu Hong Miao

Keyword(s):

Large Scale ◽

Acoustic Radiation ◽

Single Point ◽

Mechanical Vibration ◽

Sound Insulation ◽

Acoustic Performance ◽

Operating Modes ◽

Insulation Effect ◽

Vibration And Sound Radiation ◽

Insulation Performance

The acoustic performance of sound-isolating and decoupled tiles is studied from macroscopic and microscopic. First, the sound absorption and reverse sound insulation performance of sound-isolating and decoupled tiles is studied based on laminated media; then the acoustic decoupling materials influence on acoustic radiation of double cylindrical shell underwater is studied, using a double-layer cylindrical structure of large-scale as experimental model .There are large amount of operating modes designed in this experiment, such as all laying, partial laying, laying and so on. The results show that sound-isolating and decoupled tiles not only have the effect of weakening the absorption of reflections, but also have reverse sound insulation effect, which increases as frequency increases; for single point mechanical vibration, the tiles can effectively inhibit vibration and sound radiation of high frequency in the double shell.

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