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Tytuł:
Analytical Solution of the Problem of Vibration of Plates with Piezoelectric Actuators with Arbitrary Shape in Distribution Formulation
Autorzy:
Wiciak, M.
Powiązania:
https://bibliotekanauki.pl/articles/1490307.pdf
Data publikacji:
2012-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.At
43.40.Vn
Opis:
This paper is concerned with mathematical aspects of modelling vibration of a plate with piezoelectric actuators. Particularly, a thin Kirchhoff-Love plate with arbitrary shaped actuators (e.g. triangles, parallelograms, discs) is considered. The moments that act upon a structure and are induced by piezoelectric actuators, are described by the generalized tensor product of a distribution and distribution-valued function. Finally, the formula for the solution of the Cauchy problem in the class of absolutely continuous tempered distribution-valued functions is derived.
Źródło:
Acta Physica Polonica A; 2012, 121, 1A; A-142-A-147
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of a Circular Plate with Piezoelectric Actuators of Arbitrary Shape
Autorzy:
Wiciak, M.
Trojanowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/1400087.pdf
Data publikacji:
2013-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.At
43.40.Vn
Opis:
This paper is concerned with mathematical aspects and numerical modeling of vibration of a circular plate with piezoelectric actuators. Particularly, a thin Kirchhoff-Love plate with arbitrary shaped actuators (e.g. pie-shaped, trapezoid, disc, and rectangular) is considered. In the theoretical model, the moments that act upon a structure and are induced by piezoelectric actuators are described by the generalized tensor product of a distribution and distribution-valued function. Numerical computations utilize the FEM approach supported by Ansys software.
Źródło:
Acta Physica Polonica A; 2013, 123, 6; 1048-1053
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Analysis of the Effectiveness of Two-part Piezoactuators in Vibration Reduction of Plates
Autorzy:
Wiciak, M.
Trojanowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/1197498.pdf
Data publikacji:
2014-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.At
43.40.Vn
Opis:
This paper is concerned with application of piezoelements with a step change of material properties occurring in the element's plane. Each part of an element may be controlled independently. Analytical models for different shape and location of the inner part of a two-part piezoactuator are developed. Finally, results of numerical simulations concerning effectiveness in vibration reduction of piezoactuators constructed this way are presented.
Źródło:
Acta Physica Polonica A; 2014, 125, 4A; A-183-A-189
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of imbalance problem in electric motor and centrifugal pump by vibration analysis
Autorzy:
Kiliç, R.
Powiązania:
https://bibliotekanauki.pl/articles/1065743.pdf
Data publikacji:
2016-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40
Opis:
In this study, general characteristics of imbalance problem in electric motor and centrifugal pumps and the vibrations caused by these faults are discussed. The fact that frequencies would yield vibrations which were caused by imbalance problems was investigated in detail. In addition, the vibration behavior formed by the electric motor and centrifugal pump running in water pumping mode are presented as a sample case. It is observed that the imbalance problem which have occurred in the electric motor and centrifugal pump could be easily determined using the vibration analysis.
Źródło:
Acta Physica Polonica A; 2016, 130, 1; 487-491
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of Passive and Active Methods for Minimization of Sound Radiation by Vibrating Clamped Plate
Autorzy:
Kozupa, M.
Wiciak, J.
Powiązania:
https://bibliotekanauki.pl/articles/1504409.pdf
Data publikacji:
2011-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.Dx
43.40.Rj
43.40.Vn
43.50.Gf
43.50.Ki
Opis:
The paper is an analytical and experimental study of a smart structure consisting of steel plate with bonded piezoelectric transducers and porous elastomer layer. Active control of sound radiation from a plate clamped at the edge square is examined. Simulations and numerical computation of the experiment are performed in Ansys environment. Calculations of plate vibration and sound radiation under stepped harmonic force are performed. The experimental setup consists of two rooms with the test opening in between. A variety of test cases were studied for three different configurations: steel plate + piezoelectric transducer, steel plate + elastomer layer, steel plate + piezoelectric transducer + elastomer layer. The aim of the paper is to illustrate the possibilities of using piezoelectric materials as an active control with elastomer layers as passive methods in one structure to improve the transmission loss.
Źródło:
Acta Physica Polonica A; 2011, 119, 6A; 1013-1017
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Ionizing Radiation Generated by Partial Discharges
Autorzy:
Zmarzły, D.
Nagi, Ł.
Borucki, S.
Boczar, T.
Powiązania:
https://bibliotekanauki.pl/articles/1199157.pdf
Data publikacji:
2014-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.-r
43.40.Vn
43.58.Wc
Opis:
This paper presents the preliminary results of the performed experiment, based on common phenomenon of partial discharges. A simple Geiger-Muller counter (DP-66M) was used for measurement of a dose of ionizing radiation, which is accompanied by partial discharges. Values from which the radiation intensity was dependent could be controlled individually: the distance between measurer and source, as well as the voltage generating partial discharges. The obtained results indicate that in the examined phenomenon, significant dose of X-ray radiation is present. According to the Kramers-Kulenkampff theory, it depends also on the atomic number of elements involved. Using MATLAB software, the obtained data were compiled to develop suitable theory for further research study. There was also implemented fuzzification for the fuzzy logic, and the effect was the capability of forecasting radiation doses according to the fixed variables for a given material, where partial discharges were generated.
Źródło:
Acta Physica Polonica A; 2014, 125, 6; 1377-1379
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Critical Evaluation of the Vibroacoustic Criteria Used in Poland to Diagnose of Power Transformer Cores
Autorzy:
Borucki, S.
Cichon, A.
Boczar, T.
Zmarzly, D.
Powiązania:
https://bibliotekanauki.pl/articles/1399335.pdf
Data publikacji:
2013-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.-r
43.40.Vn
43.58.Wc
Opis:
The subject matter of this article concerns the diagnostic test results of transformer cores by measuring and analysing vibroacoustic signals registered during their normal operation. The main objective of this research study conducted by the authors, the results of which are published in this paper, is a critical analysis of vibroacoustic criteria, which are adopted in Poland nowadays, and based on which, the assessment of the core technical condition is performed. This article presents exemplary results that were obtained on two twin units of type TET 8509 with a power of 40 MVA. The paper specifies diagnosed structures, the measurement system applied, and the currently used methodology to assess the degree of core loosening. To determine the efficacy and assessment accuracy of the applied vibroacoustic criteria, correlation between mechanical vibration measurements of the tested transformer tanks and results obtained by gas chromatography was performed.
Źródło:
Acta Physica Polonica A; 2013, 124, 3; 391-394
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural Noise Reduction and Its Effects on Plate Vibrations
Autorzy:
Trojanowski, R.
Wiciak, J.
Powiązania:
https://bibliotekanauki.pl/articles/1490308.pdf
Data publikacji:
2012-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.Dx
43.40.-r
46.40.Ff
Opis:
The aim of this work is reduction of structural noise generated by plate and its impact on plates vibrations. For this purpose a one-side clamped aluminum plate with 5 piezo elements attached is used. One of the elements is used for plate excitation, two as vibration sensors, and two as actuators. Structural noise is measured by a microphone connected with SVAN 912 E. Study was divided into three parts: measurements of vibrations and noise generated by excited plate, active vibration control, and structural noise reduction. A significant noise local noise reduction is obtained, although with increase in plate vibrations.
Źródło:
Acta Physica Polonica A; 2012, 121, 1A; A-148-A-151
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Repeatability Estimation for Vibration Measurement Results of Power Transformer Core
Autorzy:
Borucki, S.
Cichon, A.
Skubis, J.
Boczar, T.
Powiązania:
https://bibliotekanauki.pl/articles/1198972.pdf
Data publikacji:
2014-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.-r
43.40.Vn
43.58.Wc
Opis:
The subject matter of this paper refers to the diagnostics of a transformer core, based on measurements and analysis of vibroacoustic signals registered during their normal operation. The paper presents results of the research aimed to evaluate the repeatability of vibration measurements for power transformer core. Recording of vibroacoustic signals was performed under laboratory conditions on dry-insulated transformers. The study concerned evaluation of changes in vibroacoustic indicators of the transformer core during operation with a turned and loosened core. Conclusions from the measurement results were drawn on the basis of the parametric test of significance derived from the variance analysis for many means of single classification basing on the Fisher-Snedecor F-distribution.
Źródło:
Acta Physica Polonica A; 2014, 125, 6; 1299-1302
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of Acoustic Emission Signals Generated in On Load Tap Changer
Autorzy:
Cichoń, A.
Borucki, S.
Wotzka, D.
Powiązania:
https://bibliotekanauki.pl/articles/1199209.pdf
Data publikacji:
2014-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.-r
43.40.Vn
43.58.Wc
Opis:
The paper deals with mathematical modeling of acoustic emission signals which are generated in on load tap changers. In power engineering area acoustic emission method is commonly used for diagnosis purposes. Authors in their research works apply it for detection of defects occurring in on load tap changers, which are important elements of power transformers. The acoustic emission method is based on measurements performed by use of wideband piezoelectric transducers that are mounted on transformer tank surface. The registered signal is then analyzed in the time, frequency, and time-frequency domains or is evaluated with computer expert systems for diagnosis purposes. Depending on indicators device technical condition can be determined. The contribution given by the authors in this paper is proposal of a mathematical model, which describes envelope of the measured acoustic emission signal.
Źródło:
Acta Physica Polonica A; 2014, 125, 6; 1396-1399
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solving a Set of Spherical Equations for Localization of Partial Discharges by Acoustic Emission Method
Autorzy:
Boczar, T.
Witkowski, P.
Borucki, S.
Cichoń, A.
Powiązania:
https://bibliotekanauki.pl/articles/1401873.pdf
Data publikacji:
2015-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.-r
43.40.Vn
43.58.Wc
Opis:
This article deals with the subject matter of improvement of the acoustic emission methods used for location of partial discharges, which may occur inside power transformer insulation systems. Analytical solutions of spherical equations for location of partial discharge generation using the acoustic method were shown in detail. Presented in the article method of solving the assumed equations is based on the analytical method and matrix notation. Theoretical considerations and later the measurement-based verification refer to the use of the triangulation method for location of the occurrence of partial discharges. The results of the scientific and research works that have been presented in this article are the next stage of research aimed at development of on-line diagnosis system for insulation systems of electrical equipment, allowing for detection, measurement and identification of forms and locations of partial discharges using the acoustic emission method.
Źródło:
Acta Physica Polonica A; 2015, 128, 3; 299-305
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diagnostics of the Core Mechanical Construction Based on Vibroacoustic Measurements and Distribution of Temperature Field in Transformer Magnetic Circuit
Autorzy:
Borucki, S.
Cichon, A.
Boczar, T.
Powiązania:
https://bibliotekanauki.pl/articles/1401874.pdf
Data publikacji:
2015-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.-r
43.40.Vn
43.58.Wc
Opis:
Subject matter of this article concerns the results of research works on the development and use of the vibroacoustic method to evaluate technical state of transformer cores. The article presents obtained measurement results of transformer mechanical vibration for two cases of its operation: with twisted and loosened core. In order to demonstrate negative effects of operating a transformer with a loosened core, this publication presents thermographic images showing temperature distribution on its magnetic core. The article characterises the examined transformer, employed measurement system and methodology of the completed experiment. The vibroacoustic and thermographic measurements were carried out during idle work of the transformer. Core vibration was registered for three measurement axes: 0X, 0Y and 0Z. Completed tests have proven that loosened screws pressing the core cause evident increase in the value of magnetic core vibration acceleration. At the same time, the temperature rises by more than 25%.
Źródło:
Acta Physica Polonica A; 2015, 128, 3; 306-309
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Wavelet Analysis of the Vibroacoustic Signal Measurement in a Transient State Operation of Power Transformer
Autorzy:
Borucki, S.
Cichon, A.
Boczar, T.
Zmarzly, D.
Powiązania:
https://bibliotekanauki.pl/articles/1417934.pdf
Data publikacji:
2012-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.-r
43.40.Vn
43.58.Wc
Opis:
The article presents the results of attempts made to develop a non-invasive diagnostic method of a technical state of a transformer's core based on an analysis of mechanical vibrations registered during the start-up of the transformer analyzed. The paper presents a characteristic of the transformer under study, the measuring systems applied and the method developed for assessing the degree of the core loosening. The original results presented in the paper have been obtained under laboratory conditions during tests conducted on an oil transformer of 200 kVA. The analysis of recorded virboacoustic signals was performed by means of discrete wavelet transform for three different operating cases: the transformer with no core defect, the transformer with loose screws of the magnetic circuit of the upper yoke, and the transformer with completely loosen screws of the beam of the upper yoke and the lower core. The signals have been recorded on two perpendicular measuring axes: 0X and 0Y and their measured values were subject to the wavelet analysis.
Źródło:
Acta Physica Polonica A; 2012, 122, 5; 800-803
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selecting Sensor for On Load Tap Changer Contacts Degree of Wear Diagnostics
Autorzy:
Cichoń, A.
Borucki, S.
Berger, P.
Powiązania:
https://bibliotekanauki.pl/articles/1399337.pdf
Data publikacji:
2013-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.-r
43.40.Vn
43.58.Wc
Opis:
Results of scientific research works considering selection of measuring transducer applied for registration of acoustic emission signals generated by on load tap changers are presented in the paper. During the coupling process acoustic emission signals are generated by: the mechanical setup of tap changer, contacts operation, and other phenomena. For most on load tap changers types, the working medium is insulation oil in which the acoustic wave being formed propagates to the steal tank. There exists a possibility to register acoustic emission signals with a piezoelectric transducer attached to the outer tank surface or with a hydrophone immersed in the oil. Acoustic emission signal obtained in such manner contains information which describes operation of the power tap changer and the selector. A comparative analysis of acoustic emission signals generated by on load tap changers working under laboratory conditions, with applied measuring transducers with different transmittances, is presented in the paper. The comparative analysis was performed in order to determine their suitability for on load tap changers technical condition diagnosis. Based on the results achieved, one transducer which allows the registration of acoustic events generated during on load tap changers operation was selected.
Źródło:
Acta Physica Polonica A; 2013, 124, 3; 395-398
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Time-Frequency Analysis of Mechanical Vibrations of the Dry Type Power Transformer Core
Autorzy:
Borucki, S.
Powiązania:
https://bibliotekanauki.pl/articles/1493019.pdf
Data publikacji:
2011-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.-r
43.40.Vn
43.58.Wc
Opis:
The paper presents research results referring to the development of a non-invasive method of assessment of the power transformer core technical condition based on the analysis of the mechanical vibrations registered. It characterizes the power object under study, the measuring system used and the developed methodology of assessment of the core pressing degree using the vibroacoustic method. The original results of the time-frequency analysis of the vibroacoustic signals presented in the paper were obtained during switching on a real 800 kVA dry type power transformer in laboratory conditions. The analysis of the signals registered was carried out for three states of its operation: the core pressed by the manufacturer, the core with loose screws fixing the upper yoke and the core with separated upper yoke beams.
Źródło:
Acta Physica Polonica A; 2011, 120, 4; 571-574
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vibroacoustic Measurements in a Transient State οf Transformer Operation
Autorzy:
Borucki, S.
Powiązania:
https://bibliotekanauki.pl/articles/1795788.pdf
Data publikacji:
2009-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.-r
43.40.Vn
43.58.Wc
Opis:
The subject matter of this paper refers to the assessment of the technical condition of a power transformer core and windings based on vibroacoustic measurements taken during a transient operation state of the appliance diagnosed - at a transformer unit switch on. The paper presents preliminary results of the research work carried out, which aims at elaborating a new diagnostic and assessment method of the degree of the transformer core and winding pressing using the so-called modified vibroacoustic method. The paper characterizes the measurement path and the assessment method of the core and winding pressing degree based on the selected analyses of the vibroacoustic signal registered. The original research results presented in the paper were obtained at a real 400 kV A power transformer switch on in laboratory conditions - for a regular operation condition and for modeled core damage.
Źródło:
Acta Physica Polonica A; 2009, 116, 3; 277-280
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Errors - Numerical Uncertainty - in the Identification and Estimation of Vibroacoustic Processes
Autorzy:
Batko, W.
Powiązania:
https://bibliotekanauki.pl/articles/1537333.pdf
Data publikacji:
2010-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.At
Opis:
Problems of numerical errors in the identification and estimation procedures of vibroacoustic phenomena are discussed in the hereby paper. The main attention is focussed on problems of errors generated by different algebras governing experimentally recognisable vibroacoustic effects and the algebra applied in the utilisation of procedures of their processing. Assessment of errors for elementary operations: adding, subtracting, multiplying and raising to a power - is derived. The problem of their presence in the current model solutions as well as in the implications for processes: cognitive, experimental (testing conditions) and their implementation is discussed. The postulate of the necessity of supplementing assessments of the measurement uncertainty in vibroacoustic examinations with assessments of the numerical uncertainty - are formulated. Various ways of looking for solving this problem are outlined. References to Author's and co-authors' own investigations - in this field - are also done.
Źródło:
Acta Physica Polonica A; 2010, 118, 1; 7-10
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of the Active Plate Vibration Reduction by the Parameter of the Acoustic Field
Autorzy:
Brański, A.
Szela, S.
Powiązania:
https://bibliotekanauki.pl/articles/1504199.pdf
Data publikacji:
2011-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.20.Tb
43.60.Vx
43.40.-r
43.40.+s
Opis:
Effectiveness of the active vibration reduction of triangular plate is evaluated by way of the analysis of acoustical field. The active vibration reduction is performed with actuators. The effect is measured by the analysis of the acoustical field both far distance and near one from the plate. As the control parameter, the difference between acoustical pressures is considered. The first pressure and the second one are radiated by the plate without and with the vibration reduction, respectively. The control parameter is calculated for two reduction cases. First case, when actuators are attached at so-called quasi-optimal places and second one, when they are shifted. The numerical calculations show that the acoustical field is sensitive to change of the plate active vibration reduction. It responds to even little changes of the plate vibrations in both active reduction cases mentioned above. So that it is handy indirect control parameter of the active vibration reduction.
Źródło:
Acta Physica Polonica A; 2011, 119, 6A; 942-945
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sound Radiation by Vibrating Building Partitions in Terms of Acceptable Vibration Values
Autorzy:
Szeląg, A.
Stypuła, K.
Kamisiński, T.
Powiązania:
https://bibliotekanauki.pl/articles/1196849.pdf
Data publikacji:
2014-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.20.Tb
34.50.Ez
43.40.-r
43.40.+s
Opis:
The subject of this study is an analysis of the phenomenon of sound radiation generated by vibrating building partitions in terms of acceptable vibration values set out in PN-88/B-02171: Evaluation of the vibration impact on people in buildings. The aim of the research was to determine conditions when vibration limits, determined as those providing the required human comfort according to the standard, do not meet the requirements of PN-87/B-02151/02 describing sound level limits in rooms. In order to carry out research showing the phenomenon, various aspects of sound radiation by vibrating building partitions were analyzed theoretically. It was assumed that the vibration velocity of elements did not exceed the limits specified in the standard. Calculations were carried out, in particular, for variants with variable thickness or surface of vibrating partition as well as various types of the construction material. Furthermore, the minimum vibration duration was determined for which the values of noise exceeded the sound level limits.
Źródło:
Acta Physica Polonica A; 2014, 125, 4A; A-122-A-126
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of Control Algorithm for Active Reduction of Transversal Vibrations of Beams by Piezoelectric Elements Based on Identification of Bending Moment
Autorzy:
Kozień, M.
Ścisło, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/1402183.pdf
Data publikacji:
2015-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
02.30.Jr
43.40.Ar
43.40.Cw
45.20.da
Opis:
Application of piezoelectric elements to active reduction of bending vibrations of the beams is known well in the literature. During vibrations, an external excitation may vary in the time domain, including its form in the frequency domain. It should have influence on their response. The problem of proper selection of the control parameter in the control algorithm used to reduce vibrations arises. In the article, simulations of a control algorithm based on detection of bending moment are analytically tested. The solution for the transient type of vibrations are obtained by the finite difference method (FDM). Analysis for two separated natural modes was performed. The analysis shows the possibility to design a control algorithm based on detection of the bending moment.
Źródło:
Acta Physica Polonica A; 2015, 128, 1A; A-56-A-61
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical Solutions of Excited Vibrations of a Beam with Application of Distribution
Autorzy:
Kozień, M.
Powiązania:
https://bibliotekanauki.pl/articles/1400080.pdf
Data publikacji:
2013-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
02.30.Jr
43.40.Ar
43.40.Cw
45.20.da
Opis:
In the paper, the analytical solutions of excited vibrations of the Bernoulli-Euler type beam in general case of external loading function is analyzed. The distribution theory is applied to formulate solution when the external functions are the concentrated-force type or the concentrated-moment type. Moreover, two types of excitation in time domain, harmonic and pulsed, are considered. Due to the superposition rule which can be applied in the analyzed linear case, any combination of external loading function can be formulated. The strict analytical solutions are shown for the case of simply supported beam. Describing the external load in the form of concentrated moments makes possible the analytical simulation of the reduction of vibrations of a beam by application of the piezoelectric elements which are in practice the source of external moment-type excitation put in relatively small area of action.
Źródło:
Acta Physica Polonica A; 2013, 123, 6; 1029-1033
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New Multimode Sonotrodes Models Designed for Rotary Ultrasonic Welding Systems
Autorzy:
Kogut, P.
Milewski, A.
Kardyś, W.
Kluk, P.
Gawryś, P.
Powiązania:
https://bibliotekanauki.pl/articles/1399374.pdf
Data publikacji:
2013-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.-r
43.40.+s
43.35.+d
43.38.+n
43.38.-p
46.40.-f
Opis:
The paper presents methods of designing sonotrodes, working in varied mechanical vibration modes in high power application regime such as rotary ultrasonic welding systems. The aim of the sonotrode design process is to optimize its shape to achieve the best energy efficiency for a given welding process. Sonotrode geometry influences the power transferred to the welded element because it determines the vibration amplitude distribution in the sonotrode. The most popular applications use sonotrodes designed for axial vibration. Conducted research have shown that the optimal displacement and strain distribution is achieved for sonotrodes working in various vibration modes such as axial, transverse, radial or their compositions. In the paper examples of multimode sonotrode models for various rotary ultrasonic welding technologies have been presented.
Źródło:
Acta Physica Polonica A; 2013, 124, 3; 474-478
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustic Spectra of Ultrasound Induced Cavitations in Insulating Oils
Autorzy:
Szmechta, M.
Zmarzły, D.
Boczar, T.
Lorenc, M.
Powiązania:
https://bibliotekanauki.pl/articles/1811563.pdf
Data publikacji:
2008-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.35.Ei
43.40.Le
Opis:
Acoustic emission measurement results of acoustically induced cavitation bubbles in insulating oil are presented in this paper. Spectral analysis of acquired by a broadband transducer acoustic emission signals is proposed as a diagnostic tool for estimation of aging properties of mineral insulating oils. The article describes the main parts of the designed and built measurement apparatus used for acoustic cavitation investigation in insulating oils. In this note representative results of the experimental data taken from the apparatus are shown.
Źródło:
Acta Physica Polonica A; 2008, 114, 6A; A-231-A-238
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantitative Analysis of Phase Trajectory as the Information about Technical Condition of the Object
Autorzy:
Majkut, L.
Powiązania:
https://bibliotekanauki.pl/articles/1490328.pdf
Data publikacji:
2012-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.Le
46.40.-f
Opis:
The paper aims to describe the potential use of phase trajectory for damage detection of structural components. The attractor of the examined trajectory is a static equilibrium point of the element being diagnosed. Two different damage indices are proposed to evaluate the severity of damage in the diagnosed component. The first one refers to distance between a point on a trajectory and the point which is the attractor of the trajectory. The other one relates to linearity of the Poincaré map. Effectiveness of the proposed method was evaluated on: a simple model with two degrees of freedom, data from the finite element method model of a cantilever beam with a crack, and experimental data for a cracked plate. With the proposed method, the damage can be quickly and effectively detected. By comparing the current trajectory with that from the previous diagnostic test, it is possible to establish if the nature of crack is either propagating or stationary.
Źródło:
Acta Physica Polonica A; 2012, 121, 1A; A-168-A-173
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Active Vibration Control of Rectangular Plate with Distributed Piezoelements Excited Acoustically and Mechanically
Autorzy:
Kozupa, M.
Wiciak, J.
Powiązania:
https://bibliotekanauki.pl/articles/1537473.pdf
Data publikacji:
2010-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.Dx
43.50.-x
Opis:
The paper presents simulations and research results of testing of the aluminium plate with active vibration control. The aim of this paper is to analyze and compare two ways of excitation of the test plate, various influence on its vibrations and active damping control. Vibration control of the smart structure is realized through four piezoceramic PZT actuators and one PZT sensor bonded to the plate. Simulations and numerical computations of the structure are performed in ANSYS environment. Measurements are executed on specialized sound insulation suite for small elements in reverberation chamber. At the beginning white noise sound source is used in purpose to measure basic vibration modes. After numerical computations and measurements three particular frequencies has been chosen and for them active damping is applied. There are two ways of exciting the test plate; first method is sound wave, second is mechanical vibrations via one of piezoceramics. The test results indicate that PZTs can decrease vibrations by approximately 15 dB for a pure sound input with acoustic excitation method, for mechanical excitation method 18 dB for a sinus vibration signal is achieved.
Źródło:
Acta Physica Polonica A; 2010, 118, 1; 95-98
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selecting Mother Wavelet for Wavelet Analysis of On-Load Tap Changer Acoustic Emission
Autorzy:
Cichoń, A.
Berger, P.
Wotzka, D.
Powiązania:
https://bibliotekanauki.pl/articles/1401875.pdf
Data publikacji:
2015-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.-r
43.58.Wc
Opis:
Wavelet transformation is one of the most popular tools for acoustic signal analysis. It provides good resolution both in time and frequency domains as well as wide choice of mother wavelets - this makes wavelet transformation a choice when flexible approach is required. However, selecting parameters of analysis can be difficult, especially regarding mother wavelet as different mother wavelets have various properties regarding number of vanishing moments and symmetry. This paper presents studies to determine the possibility of on-load tap changer wear detection by applying wavelet transformation. In research, different mother wavelets were selected and their usefulness was examined. Signals to be analyzed were obtained during on-load tap changer operation in different mechanical conditions - simulating devices wear in service. All measurements were performed on model very similar to real industrial on-load tap changer. Tests were conducted in controlled laboratory environment, reducing most of the possible disruptions.
Źródło:
Acta Physica Polonica A; 2015, 128, 3; 310-314
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical Determination of the PZTs Distribution in Active Beam Vibration Protection Problem
Autorzy:
Brański, A.
Lipiński, G.
Powiązania:
https://bibliotekanauki.pl/articles/1504198.pdf
Data publikacji:
2011-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.Tm
43.40.Vn
77.65.-j
46.40.-f
62.25.Jk
Opis:
The paper concerns an active vibration protection (p-reduction) of the structure via piezoelectric transducers; p-reduction corresponds to an active vibration reduction (a-reduction). The quantity and effectiveness of the (a- or p-) reduction, among other parameters, depend on the piezoelectric transducers distribution on the structure. The best results are obtained bonding piezoelectric transducers to the structure in the sub-domains with the largest curvatures; it is so-called quasi-optimal distribution of the piezoelectric transducers. Up to now, the quasi-optimal distribution was determined based on heuristic reasons only. The aim of the paper is to confirm quasi-optimal distribution in analytical way. The beam clamped at one end, vibrating with first three modes separately, is chosen as the research object. It is assumed that the piezoelectric transducers are exactly the same. Demanding the vibration amplitude to be equal to zero (i.e. p-reduction condition), the general formula for interacting forces piezoelectric transducers-beam is derived. Next, such an appropriate distribution of piezoelectric transducers is searched analytically, that the minimal forces are achieved; it leads to the best reduction effectiveness. It turned out that the analytical method pointed out quasi-optimal distribution of the piezoelectric transducers. The validation of theoretical considerations is confirmed numerically.
Źródło:
Acta Physica Polonica A; 2011, 119, 6A; 936-941
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of Material Composition of Piezoelectric Elements with Chosen Shapes on Plate Vibration Reduction
Autorzy:
Wiciak, J.
Trojanowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/1197495.pdf
Data publikacji:
2014-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.-r
43.28.Js
46.40.Ff
Opis:
This paper presents numerical analysis of efficiency of different shapes and material composition of piezoelectric actuators used for vibration reduction. Four numerical models representing a plate clamped on all sides with two attached piezoelectric elements were created. For each model, one element had the same shape and composition and was used for plate excitation, and the other one, used for vibration reduction, had different shape and possibly material composition and could be of square or circular shape with either homogeneous or two-part material composition. Two modes were taken into account: the first mode and the fifth mode. Analysis of results was performed with ANSYS software.
Źródło:
Acta Physica Polonica A; 2014, 125, 4A; A-179-A-182
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of Vibration and Acoustic Pressure Reduction Using Different Types of Piezo actuators
Autorzy:
Wiciak, J.
Trojanowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/1402184.pdf
Data publikacji:
2015-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.-r
43.28.Js
46.40.Ff
Opis:
This paper presents results of numerical simulations on reduction of sound pressure radiated from a square plate using different types of piezo actuators. For this purpose a FEM model was developed using ANSYS software with said steel plate with a hemisphere of air on one side of the plate. There are two criteria by which the reduction is measured: minimising vibrations of plate area and minimising sound pressure on a half sphere surrounding the plate. Changes in the results for both the radiated sound pressure and plate vibration are discussed.
Źródło:
Acta Physica Polonica A; 2015, 128, 1A; A-62-A-66
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of Efficiency of Different Shapes of Homogeneous and Two-Part Piezo Elements on Vibration Reduction
Autorzy:
Trojanowski, R.
Wiciak, J.
Powiązania:
https://bibliotekanauki.pl/articles/1418045.pdf
Data publikacji:
2012-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.28.Js
43.40.-r
46.40.Ff
Opis:
The subject of this work is a numerical analysis of efficiency of different piezo element shapes and types used for vibration (and later structural sound) reduction. The shapes of both types of piezo elements used are as follows: square, right-angled triangle, and parallelogram. There are 2 types of piezo elements used in this study: homogeneous elements and elements consisting of 2 parts (inner and outer) of different composition. These are attached to steel plate clamped on all sides. For every simulation 5 elements are used as actuators, with 1 as disturbance source, and other 4 as active dampers. On the other side of a plate 4 elements are placed acting as vibration sensors. The actuator used as a disturbance source as well as sensors are always in the shape of a square. 4 modes were taken into account (analyzed each one singular and all together). Analyses were made with the use of ANSYS software.
Źródło:
Acta Physica Polonica A; 2012, 122, 5; 905-907
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Predictive Maintenance System in Drinking Water Pumping Stations
Autorzy:
Kiliç, R.
Kozan, R.
Karayel, D.
Özkan, S.
Powiązania:
https://bibliotekanauki.pl/articles/1031568.pdf
Data publikacji:
2017-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.-r
62.25.Jk
Opis:
Pumping stations are some of the most important facilities of water administration. Continuous operation of these facilities is of utter importance, to be able to serve at all times. Maintenance of these facilities is also crucial for uninterrupted operation. In this study, the functioning of the predictive maintenance technique, which is based on the vibration analysis, is briefly addressed, and the application of the technique in a real system is presented. In the real system, the steps that must be done in order to apply this system are shown step-by-step. At the end of the study, the failures determined by using the predictive maintenance method are analyzed, and solution suggestions are presented.
Źródło:
Acta Physica Polonica A; 2017, 132, 3; 1016-1021
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Analysis of Wind Turbine Construction Safety System that Uses Vibroacoustic Diagnostics
Autorzy:
Szmechta, M.
Powiązania:
https://bibliotekanauki.pl/articles/1399405.pdf
Data publikacji:
2013-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
02.60.Lj
43.40.Le
Opis:
The paper presents an analysis of the results of monitored on-line Enercon E40/6.44 wind turbine with gearless designed synchronous generator and a nominal power of 600 kW. In recent months, this plant underwent with high frequency emergency stopped, the source of which was the acceleration control system located in the nacelle. This situation causes significant and unnecessary overload of the power plant components but most of all causes significant losses of production of renewable energy due to operational downtime. This article analyzes the circumstances of errors reported by the turbine control system associated with the acceleration sensor based on data recorded during several months of using on-line SCADA system. An assessment of the impact of a number of indicators related to the wind speed and direction of the nacelle on the operation of the safety system of the turbine has been carried out. Also the possible causes of irregularities were proposed, which may be the subject of further research, especially with the use of advanced diagnostics based on vibroacoustic method.
Źródło:
Acta Physica Polonica A; 2013, 124, 3; 574-577
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Frequency and Time-Frequency Analysis of Acoustic Cavitation Noise in Insulating Oils
Autorzy:
Szmechta, M.
Boczar, T.
Frącz, P.
Powiązania:
https://bibliotekanauki.pl/articles/1493273.pdf
Data publikacji:
2011-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
02.60.Lj
43.40.Le
Opis:
The paper presents some observations of ultrasound induced cavitation phenomenon in a mineral insulating oil. The acoustic cavitation phenomenon was generated at different signal frequencies and rms voltage value supplied to round piezoelectric transducers. Used transducers have created a high energy acoustic field in prepared insulating oil samples. The acoustic emission signal contains a broad-band noise and a fundamental frequency component and its harmonics, produced by the direct driving acoustic field. The paper presents the spectral analysis of acoustic emission signal observed during acoustic cavitation in insulating oils. To emphasize the changes in acoustic cavitation intensity also time-frequency analysis was used and some spectrograms were evaluated. The measurement uncertainty of some frequency-rms voltage pairs was very unfavorable. The main application expected with created cavitation measurement system is to develop a diagnostic tool for the aging of oil, based on the hypothesis that the measured cavitation intensity and spectrum could be affected by aging. Previous published measurements showed some relationship between insulating oil aging process and changes of acoustic emission of cavitations.
Źródło:
Acta Physica Polonica A; 2011, 120, 4; 744-747
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical Model and Numerical Analysis of~AE Wave Generated by Partial Discharges
Autorzy:
Wotzka, D.
Boczar, T.
Fracz, P.
Powiązania:
https://bibliotekanauki.pl/articles/1493290.pdf
Data publikacji:
2011-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.Le
02.60.Lj
Opis:
Paper presents definition of a mathematical model describing acoustic emission signals generated by partial discharges occurring in oil immersed electric power transformers. Time runs, power spectral density graphs and spectrograms of acoustic emission signals generated in experiments, performed under laboratory conditions, and of equivalent signals, calculated on the basis of the mathematical model, are presented. Furthermore, results of numerical simulations of acoustic pressure distribution inside a tank filled with insulation oil are presented in the paper. In the center of the tank acoustic emission wave sources were placed, each generating signals described by the model developed.
Źródło:
Acta Physica Polonica A; 2011, 120, 4; 767-771
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Use of 3D Modeling in the Diagnosis of Power Capacitors with Acoustic Emission Method
Autorzy:
Boczar, T.
Błachowicz, A.
Borucki, S.
Zmarzły, D.
Powiązania:
https://bibliotekanauki.pl/articles/1417933.pdf
Data publikacji:
2012-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.Le
07.05.Tp
Opis:
The article presents the issue modelling the partial discharge phenomenon in engineering and scientific environments using hardware-based computer cluster. The authors present the results of research work on the phenomenon of acoustic emission from partial discharge occurring in power capacitors for power factor correction. The work includes the issues presentation and explanation of solutions enabling to create 3D spatial model of power capacitor. The authors proposed a simplified model of an acoustic test object aimed at improving the process of calculating the results.
Źródło:
Acta Physica Polonica A; 2012, 122, 5; 796-799
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Sound Source Directivity on Acoustics Parameters Distribution in Kraków Opera House
Autorzy:
Gołaś, A.
Suder-Dębska, K.
Filipek, R.
Powiązania:
https://bibliotekanauki.pl/articles/1537421.pdf
Data publikacji:
2010-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.55.Ka
43.20.Dk
43.40.Rj
Opis:
Determining of Kraków Opera House's basic acoustics parameters by using numerical simulations is presented in the paper. Parameters have been obtained by using numerical simulation methods. Sound sources have been created by means of FEA, however acoustic field distributions have been analysed by geometrical methods. Apart from the room parameters definition, it is necessary to determine sound source parameters like acoustic power level and directivity pattern. In the simplest case, the sound source can be assumed as omni-directional point source. However it does not reflect most real-live sources precisely. When the literature and databases do not contain any information about the sound source directivity pattern, it can be obtained numerically using FEA. First, the sound source model is created, and then results from its spherical boundary are used to define the source in a program based on geometrical methods. Here have been analysed several distributions of acoustic parameters like: Direct Energy, Sound Pressure Level (SPL), Clarity index (C80) etc. The results indicate that influence of sound source directivity on acoustics parameters changes is essential.
Źródło:
Acta Physica Polonica A; 2010, 118, 1; 62-65
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Asymptotic Formulae of the Modal Acoustic Impedance for the Asymmetric Vibrations of a Clamped Circular Plate
Autorzy:
Rdzanek, W.
Szemela, K.
Powiązania:
https://bibliotekanauki.pl/articles/1537549.pdf
Data publikacji:
2010-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.20.Ks
43.20.Rz
43.40.+s
Opis:
The asymptotic and approximate formulae for the asymmetric modal acoustic self- and mutual-impedance have been presented for a clamped circular plate embedded into a flat rigid baffle. The formulae have been obtained for the wide frequency band covering the low frequencies, the high frequencies and the middle frequencies. The high frequency asymptotics have been achieved using the method of contour integral and the method of stationary phase. The products of the Bessel and Neumann functions have been expressed as the asymptotic expansions. Further, the approximate formulae valid within the low and middle frequencies have been obtained from the high frequency asymptotics using some mathematical manipulations. The formulae presented are valid for both the axisymmetric vibrations and the asymmetric vibrations.
Źródło:
Acta Physica Polonica A; 2010, 118, 1; 141-154
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustic Nearfield and Farfield for Vibrating Piston in Geometrical and Intensity Formulations
Autorzy:
Kozień, M.
Powiązania:
https://bibliotekanauki.pl/articles/1490305.pdf
Data publikacji:
2012-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.20.Bi
43.20.Tb
43.40.Rj
Opis:
In classic acoustics there are two areas identified around acoustic sources - nearfield and farfield. The nearfield is connected with the Fresnel solution and farfield - the Fraunhofer one. For each regions there are different theoretical formulae for determination of distribution of the chosen acoustic parameter. Unfortunately there is no sharply outlined border between regions. Therefore one of the important problem, is to define approximately conditions for state the border between them. The two attempts for identification are discussed, i.e. geometrical one and intensity ones. The results are shown on the vibrating circular rigid piston case.
Źródło:
Acta Physica Polonica A; 2012, 121, 1A; A-132-A-135
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wave Intensity Distributions in Complex Structures
Autorzy:
Tanner, G.
Chappell, D.
Maksimov, D.
Powiązania:
https://bibliotekanauki.pl/articles/1492500.pdf
Data publikacji:
2011-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.Dx
43.20.Dk
43.20.Rz
Opis:
The vibro-acoustic response of mechanical structures can in general be well approximated in terms of linear wave equations. Standard numerical solution methods comprise the finite or boundary element method in the low frequency regime and statistical energy analysis in the high-frequency limit. Major computational challenges are posed by the so-called mid-frequency problem - that is, composite structures where the local wavelength may vary by orders of magnitude across the components. Recently, a new approach towards determining the distribution of mechanical and acoustic wave energy in complex built-up structures improving on standard statistical energy analysis has been proposed. The technique interpolates between statistical energy analysis and ray tracing containing both these methods as limiting cases. The method has its origin in studying solutions of wave equation with an underlying chaotic ray-dynamics - often referred to as wave chaos. Within the new theory - dynamical energy analysis - statistical energy analysis is identified as a low resolution ray tracing algorithm and typical statistical energy analysis assumptions can be quantified in terms of the properties of the ray dynamics. We have furthermore developed a hybrid statistical energy analysis/finite element method based on random wave model assumptions for the short-wavelength components. This makes it possible to tackle mid-frequency problems under certain constraints on the geometry of the structure. Dynamical energy analysis and statistical energy analysis/finite element method calculations for a range of multi-component model systems will be presented. The results are compared with both statistical energy analysis results and finite element method as well as boundary element method calculations. Dynamical energy analysis emerges as a numerically efficient method for calculating mean wave intensities with a high degree of spatial resolution and capturing long range correlations in the ray dynamics.
Źródło:
Acta Physica Polonica A; 2011, 120, 6A; A-172-A-177
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sound Synthesis Using Physical Modeling on Heterogeneous Computing Platforms
Autorzy:
Pluta, M.
Borkowski, B.
Czajka, I.
Suder-Dębska, K.
Powiązania:
https://bibliotekanauki.pl/articles/1402176.pdf
Data publikacji:
2015-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.Dx
43.58.Ta
43.75.Zz
Opis:
The paper presents a comparison of central processing unit (CPU) and graphics processing unit (GPU) performance in sound synthesis based on physical modeling. The goal was to achieve real-time performance with two- and three-dimensional finite difference (FD) instrument models. Two abstract instruments, a membrane and a block, were modeled and tested using a CPU and a GPU in the OpenCL framework to find a threshold of real-time model size. Two different algorithms were compared. With a parallelized algorithm, a middle-class GPU outperformed a top-class CPU by factor of 2.5 in 2D and by factor of 7.5 in 3D model. Synchronization issues in parallel GPU calculations were discussed and addressed. The results show that GPUs can significantly speed up real-time musical instrument simulations, allowing for developing more complex and realistic models.
Źródło:
Acta Physica Polonica A; 2015, 128, 1A; A-22-A-28
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phononic Band Gap Width Control through Structural and Material Parameters in Two-Dimensional Phononic Crystals
Autorzy:
Śliwa, I.
Krawczyk, M.
Powiązania:
https://bibliotekanauki.pl/articles/2044562.pdf
Data publikacji:
2005-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.20.+g
43.35.+d
43.40.+s
Opis:
The phononic band structures of two-dimensional solid phononic crystals with different lattice and scatterer symmetry are studied numerically, with three types of lattice (square, triangular, and rectangular) and four different scatterer shapes (circle, hexagon, square, and rectangle) considered. XY and Z vibration modes are investigated separately. Two types of phononic crystal are considered: one composed of high-density rods embedded in a low-density matrix, the other of low-density rods in a high-density matrix. In the former case, lattice type and polarization being fixed, the broadest gaps are obtained when the symmetry of the rods corresponds to that of the lattice (the shape of a rod is identical with that of the first Brillouin zone); the largest gap width values are observed in triangular lattice-based crystals (compared to those based on the square and rectangular lattices), the shape of the corresponding first Brillouin zone being closest to a circle. These rules do not apply to structures in which the density of the rod material is lower than that of the matrix. In this case, when the symmetry of the rods corresponds to that of the lattice, gaps either fail to appear at all, or are much narrower than in other configurations. The effect of other material parameter values (such as the longitudinal and transversal velocity values) on the relation between the energy gap width and the scatterer symmetry is found to be much lesser.
Źródło:
Acta Physica Polonica A; 2005, 108, 6; 943-957
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical Determination of Optimal Actuators Position for Single Mode Active Reduction of Fixed-free Beam Vibration Using the Linear Quadratic Problem Idea
Autorzy:
Żołopa, E.
Brański, A.
Powiązania:
https://bibliotekanauki.pl/articles/1196911.pdf
Data publikacji:
2014-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.Tm
43.40.Vn
77.84.Dy
77.65.-j
46.40.-f
62.25.Jk
Opis:
An analytical solution is obtained, based on linear quadratic problem well-known in the control theory. The problem is formulated for fixed-free beam vibration (fourth order partial differential equation) in Hilbert space and the point control and distributed output is considered. Beam deflection at any point is chosen as a criterion of optimization. In this case it means the linear quadratic problem. Up to now, the linear quadratic problem was formulated many times, but only for the time-dependent equation. The aim of the paper is to obtain the value of the cost functional formulated as the function of distribution of actuators. The minimum of this function leads to the optimal actuators location. The results obtained with this method confirm the results obtained in heuristic way and pure analytical one for separate mode; it is pointed out that the actuators ought to be bonded on the beam sub-regions in which the mode curvatures take their local maximums and the highest value.
Źródło:
Acta Physica Polonica A; 2014, 125, 4A; A-155-A-158
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effectiveness Analysis of the Beam Modes Active Vibration Protection with Different Number of Actuators
Autorzy:
Brański, A.
Powiązania:
https://bibliotekanauki.pl/articles/1400105.pdf
Data publikacji:
2013-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.Tm
43.40.Vn
77.84.Dy
77.65.-j
46.40.-f
62.25.Jk
Opis:
This paper deals with an active vibration protection (p-reduction) of the beam-actuators mechanical system, hence it concerns separate modes. The paper's aim is an effectiveness analysis of the p-reduction assuming different number of actuators. It is assumed a priori that actuators are bonded to the beam in the sub-domain with the largest curvatures and they are exactly the same. The beam clamped at one end is chosen as the research object. Next, as required by the p-reduction condition, the number and distribution of actuators are changed. It turns out that the best reduction effectiveness, measured via any effectiveness coefficient, is obtained for one actuator bonded in the sub-domain with the largest curvature. The validation of theoretical considerations is confirmed numerically.
Źródło:
Acta Physica Polonica A; 2013, 123, 6; 1123-1127
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Strain-dependent damping of Ti-10V-2Fe-3Al at room temperature
Autorzy:
Göken, J.
Fayed, S.
Skubisz, P.
Powiązania:
https://bibliotekanauki.pl/articles/1058185.pdf
Data publikacji:
2016-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.72.Hh
43.40.Cw
43.58.Fm
Opis:
The Ti-10V-2Fe-3Al alloy is advantageous over other titanium grades due to its high tensile strength and its high resistance against creep, cracking, and corrosion. The investigated alloy was hammer-forged inducing high strain rates in the material at a temperature of 800°C and underwent different cooling procedures. Three in that way thermomechanically treated specimens were prepared for subsequent study of the vibration behaviour of the material with the help of non-destructive, contact-free acoustic measurements. Resulting time-dependent decaying acoustic signals were analysed to investigate the dependence of the material damping behaviour on the individual downstream thermal treatment procedure and, ultimately, on the microstructural changes.
Źródło:
Acta Physica Polonica A; 2016, 130, 6; 1352-1357
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Alarm Siren Structure Parameters on Output Sound Pressure Level
Autorzy:
Wiciak, J.
Dąbrowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/1490306.pdf
Data publikacji:
2012-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.38.Fx
43.40.At
77.65.Bn
Opis:
The paper is a discussion of the construction of an alarm siren based on the active piezoelectric element. The influence of various parameters on the loudness of the siren was investigated. Efforts to increase the efficiency of selected design were made. The simulations carried out based on an ANSYS. Individual dimensions of a piezoelectric transducer were selected as well as a collaborate diaphragm. The possibility of using different piezoelectric materials was also analyzed. All tasks and computer simulations were aimed at receiving a siren structure able to obtain the highest sound pressure level at selected frequency.
Źródło:
Acta Physica Polonica A; 2012, 121, 1A; A-136-A-141
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diagnostic Inferring on the Bases of Nonlinear Models
Autorzy:
Dąbrowski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1537405.pdf
Data publikacji:
2010-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.Ga
45.80.+r
46.40.Ff
Opis:
Physical phenomena accompanying destruction processes of technical systems are nonlinear and "low-energetic" by nature, while during wearing out mainly a nonlinear disturbance changes. Out of many inference techniques - on the observation basis of the state of the system - the best one is undoubtedly the well-defined mathematical model, allowing inferring `backwards' and `forward', which means finding the genesis and prognosis of the phenomenon. However, such model should be nonlinear. Problems related to the identification of nonlinear dynamic models in a frequency domain and a proposition of solving this problem for the needs of technical diagnostics, i.e. in situations when the observed wear out effects are significantly smaller than the dynamic effects - are discussed in the hereby paper. The bases of the proposed method constitute the discussion of possible solutions of a certain class of nonlinear differential equations and resulting from that statements on the possibility of nonlinear disturbance approximations by a series of the selected harmonic frequencies.
Źródło:
Acta Physica Polonica A; 2010, 118, 1; 45-48
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Vibro-Acoustic Signals Generated during Operation of Micro Wind Turbines
Autorzy:
Wotzka, D.
Boczar, T.
Malec, T.
Pierzga, R.
Powiązania:
https://bibliotekanauki.pl/articles/1399411.pdf
Data publikacji:
2013-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
88.50.jj
88.50.gp
43.40.At
Opis:
Results of a measurement and analysis of vibro-acoustic signals generated by two low power vertical-axis wind turbines that are installed on the roof of the Electric Power Institute at Opole University of Technology are presented in the paper. The study considers a Darrieus and a Savonius type wind turbines of rated power 1 kW each. For registration of the vibrations of the turbine mast three uniaxial accelerometers and a measurement equipment from Brüel & Kjær were applied. The measurement setup is presented in the paper. A comparative analysis of the registered data in the time and time-frequency domains was performed. Results depict changes in the recorded signals in time and frequency under different meteorological conditions, i.e. for different wind speed values. Based on the achieved results significant differences in the mast vibrations of the two kinds of wind turbines were stated.
Źródło:
Acta Physica Polonica A; 2013, 124, 3; 595-597
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical Model for Explosive-Driven Ultracompact Shock-Wave Ferromagnetic Generators
Autorzy:
Talantsev, E.
Shkuratov, S.
Baird, J.
Altgilbers, L.
Powiązania:
https://bibliotekanauki.pl/articles/1807897.pdf
Data publikacji:
2009-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
62.50.+p
75.50.Ww
43.40.Jc
Opis:
An analytical model of the operation of recently invented ultracompact explosive-driven shock-wave ferromagnetic generators that utilize longitudinal (shock wave propagates along the magnetization vector) and transverse (shock wave propagates across the magnetization vector) shock wave demagnetization of $Nd_{2}Fe_{14}B$ hard ferromagnets, and an analytical technique for calculation of amplitudes of the current pulse produced by the generators were developed. The model utilizes the magnitude of the energy product, $(BH)_\text{max}$, and the magnetostatic energy of the hard ferromagnetic element of the ferromagnetic generator as parameters for determining ferromagnetic generator pulse generation, and it does not consider the magnitude of remnant magnetization, B_{r}, of the ferromagnetic material. The developed technique for calculation of the current pulse amplitude produced by the ferromagnetic generator provides comprehensive and accurate results. Amplitudes of calculated ferromagnetic generator output currents are in good agreement with experimentally obtained data.
Źródło:
Acta Physica Polonica A; 2009, 115, 6; 1028-1030
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Anusual Application of Partial Discharges to Diagnose of High Voltage Power Transformers
Autorzy:
Gacek, Z.
Szadkowski, M.
Malitowski, G.
Witos, F.
Olszewska, A.
Powiązania:
https://bibliotekanauki.pl/articles/1493101.pdf
Data publikacji:
2011-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.Le
52.80.s
07.50.Hp
Opis:
The article contains information on research carried out in Electric Faculty of Silesian University of Technology, made at test stations and aimed at diagnosis how is actual technical state of high voltage power oil transformers. Opinion on a state of transformers is based on analysis results of partial discharge measurements. Authors use simultaneously: electric, acoustic and dissolved gas analysis method. Applied acoustic method is the original own one. Non-conventional application of electric method is proposed, too. In the frame of chosen methodology the partial discharges are measured and next calculations of quantities describing partial discharges within particular methods are carried out in order to describe phenomena commonly for electric and acoustic method. Information sources about level and kind of partial discharges are measurement results obtained from electric method whereas information on places where partial discharges appear is contained in measurement results coming from acoustic method. Authors present selected application results of such a combined measuring method.
Źródło:
Acta Physica Polonica A; 2011, 120, 4; 609-615
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impulse and Resonant Response in Systems Showing Secular and Leaky Excitations
Autorzy:
Sobieszczyk, P.
Gałązka, M.
Trzupek, D.
Zieliński, P.
Powiązania:
https://bibliotekanauki.pl/articles/1399034.pdf
Data publikacji:
2013-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.20.Ks
68.35.Ja
43.40.+s
91.30.Fn
Opis:
A model consisting of a string embedded in an elastic medium and terminated by a harmonic oscillator has been studied in the frequency and time domains to elucidate the physical effects of supersonic and subsonic leaky waves as well as that of true surface waves. A supersonic leaky wave manifests itself by a resonant maximum of the local density of states within the band of bulk waves and by an anomalous dispersion of the real part of the frequency dependent response function. The time domain impulse response then contains mainly resonant contribution from the poles of the response function in analogy to ordinary resonances. True surface waves show generally analogous behaviour. Here, however, the phenomenon is governed by dissipation mechanisms different from the radiation into the bulk. An important difference is that the impulse response contains equilibrated contributions due to the poles and due to the stop frequency gap in the case of true surface waves. The main manifestation of a subsonic leaky wave, i.e. a surface resonance with the frequency situated in the stop gap, is a sharp peak of the real part of the frequency-dependent response function just at the bottom of the bulk waves band. This is in certain analogy with a large reactive power in electric circuits. A strong destructive interference of the resonant part of the impulse response with the part due to the gap makes the time domain response fast attenuated.
Źródło:
Acta Physica Polonica A; 2013, 124, 6; 1020-1024
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
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