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    Wyświetlanie 1-15 z 15
    Tytuł:
    Wave Propagation in a LRPC Composite Double Panel Structure with Periodically Attached Pillars and Etched Holes
    Autorzy:
    Qian, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/176620.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    locally resonant phononic crystal
    composite double panel structure
    band structure
    displacement field
    transmission power spectrum
    “base-spring-mass” simplified model
    Opis:
    The locally resonant phononic crystal (LRPC) composite double panel structure (DPS) made of a twodimensional periodic array of a two-component cylindrical LR pillar connected between the upper and lower composite plates is proposed. The plates are composed of two kinds of materials and periodically etched holes. In order to reveal the bandgap properties of structure theoretically, the band structures, displacement fields of eigenmodes and transmission power spectrums of corresponding 8 × 8 finite structure are calculated and displayed by using finite element method (FEM). Numerical results and further analysis demonstrate that if the excitation and response points are picked on different sides of the structure, a wide band gap with low starting frequency is opened, which can be treated as the coupling between dominant vibrations of pillars and plate modes. In addition, the influences of filled-in rubber, etched hole and viscidity of soft material on band gap are studied and understood with the help of “base-spring-mass” simplified model.
    Źródło:
    Archives of Acoustics; 2018, 43, 4; 717-725
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Using PWE/FE Method to Calculate the Band Structures of the Semi-Infinite PCs : Periodic in x-y Plane and Finite in z–direction
    Autorzy:
    Qian, D.
    Shi, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/176974.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    semi-infinite phononic crystal
    coupled plane wave expansion
    finite element method
    band structure
    Opis:
    This paper introduces the concept of semi-infinite phononic crystal (PC) on account of the Infinite periodicity in x-y plane and finiteness in z-direction. The plane wave expansion and finite element methods are coupled and formulized to calculate the band structures of the proposed periodic elastic composite structures based on the typical geometric properties. First, the coupled plane wave expansion and finite element (PWE/FE) method is applied to calculate the band structures of the Pb/rubber, steel/epoxy and steel/aluminum semi-infinite PCs with cylindrical scatters. Then, it is used to calculate the band structure of the Pb/rubber semi-infinite PC with cubic scatter. Last, the band structure of the rubbercoated Pb/epoxy three-component semi-infinite PC is calculated by the proposed method. Besides, all the results are compared with those calculated by the finite element (FE) method implemented by adopting COMSOL Multiphysics. Numerical results and further analysis demonstrate that the proposed PWE/FE method has strong applicability and high accuracy.
    Źródło:
    Archives of Acoustics; 2017, 42, 4; 735-742
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Effect of Layer Thickness on the Reflectance of a Quasi One-Dimensional Composite Built with Zr55Cu30Ni5Al10 Amorphous Alloy and Epoxy Resin
    Autorzy:
    Garus, Sebastian
    Sochacki, Wojciech
    Powiązania:
    https://bibliotekanauki.pl/articles/2049717.pdf
    Data publikacji:
    2021
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    amorphous alloy
    aperiodic multilayer
    mechanical waves
    phononic crystal
    bandgap
    Opis:
    The study examined the impact of the angle of incidence of mechanical waves on various types of quasi one-dimensional superlattice. Binary periodic structure, quasi-periodic distribution of Thue-Morse layers and Severin’s aperiodic multilayer were used. Using the concatenation and recursive rules, the distribution of layers was determined for individual structure types for generation numbers equal to 3, 4 and 5. The structures were selected so that the thickness of the composite was the same for each type of distribution for a given generation number value. Transfer Matrix Method algorithm was used to determine reflectance. The band structure of reflectance has been demonstrated for incidence angles up to 90 degrees at mechanical wave frequencies up to 50 kHz. The existence of wide bands of high reflectance above the acoustic frequencies was demonstrated for the analyzed structures. Increasing the layer thickness caused an inhomogeneous shifts of transmission peaks towards lower frequencies.
    Źródło:
    Archives of Metallurgy and Materials; 2021, 66, 2; 503-510
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Propagation characteristics of longitudinal-torsion coupled waves in phononic crystal rods of chiral materials
    Autorzy:
    Dai, P.
    Wang, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/38697111.pdf
    Data publikacji:
    2023
    Wydawca:
    Instytut Podstawowych Problemów Techniki PAN
    Tematy:
    chiral material
    band gap
    phononic crystal rods
    longitudinal-torsion waves
    Opis:
    The chiral properties of chiral materials have a great influence on the wave propagation. Applying chiral materials to the design of phononic crystal rods not only increases the design space, but also may have other potential advantages. There is a lack of research on designing phononic crystal rods using chiral materials and the propagation characteristics of elastic waves in phononic crystal rods made of chiral materials. In this study, chiral materials are introduced into the design of phonon crystal rods for the first time, Bragg scattering type and local resonance type phononic crystal rods are designed using chiral materials. Dispersion equations for the propagation of longitudinal-torsion coupled waves in the phononic crystal rods are derived, and the effect of the chirality of the materials on their bandgap range is studied. The study shows that: in Bragg scattering type phonon crystal rods, material chirality can greatly affect the bandgap, among them, the chiral direction has the greatest effect, and in order to obtain a low-frequency wide bandgap, the chiral coefficients of the materials should be increased as much as possible with the chiral directions of the two cells being opposite; in the local resonance type phonon crystal rod, only two types of oscillators are added to the material simultaneously to produce a band gap, and the starting frequency obtained is much lower than that of the Bragg scattering type.
    Źródło:
    Archives of Mechanics; 2023, 75, 5; 543-558
    0373-2029
    Pojawia się w:
    Archives of Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Optimization of a Bandgap in the Ultrasonic Phononic Coating
    Autorzy:
    Garus, Sebastian
    Sochacki, Wojciech
    Garus, Justyna
    Sandu, Andrei Victor
    Powiązania:
    https://bibliotekanauki.pl/articles/2049725.pdf
    Data publikacji:
    2021
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    reflectance coating
    mechanical waves
    phononic crystal
    band gap
    optimization
    Opis:
    This work concerns the study of the coatings for the ultrasound frequency range as a quasi one-dimensional phononic crystal structure protecting a sea object against high resolution active sonar in the frequency range most commonly found for this type of equipment. The topology of the examined structure was optimized to obtain a band gap in the 2.2-2.3 MHz frequency band. For this purpose, a genetic algorithm was used, which allows for optimal distribution of individual elements of the ultrasound multilayer composite. By optimal distribution is meant to achieve a structure that will allow minimal reflectance in a given frequency range without height reflectance peaks with a small half width. Analysis of the wave propagation was made using the Transfer Matrix Method (TMM). As part of the research, 15 and 20-layer structures with reflectance at the level of 0.23% and 0.18%, respectively, were obtained. increasing the number of layers in the analyzed structures resulted in finding such a distribution in which a narrow band of low reflectance was obtained, such distributions could also be used as bandpass filters. The use of a genetic algorithm for designing allows to obtain modern coatings, the characteristics of which result from the structure.
    Źródło:
    Archives of Metallurgy and Materials; 2021, 66, 2; 537-542
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    One dimensional phononic FDTD algorithm and transfer matrix method implementation for Severin aperiodic multilayer
    Autorzy:
    Garus, S.
    Sochacki, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/122705.pdf
    Data publikacji:
    2017
    Wydawca:
    Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
    Tematy:
    phononic
    FDTD
    transfer marix
    aperiodic
    multilayers
    właściwości transmisyjne
    urządzenia akustyczne
    aperiodyczna supersieć
    Severin
    Opis:
    In this paper, the power spectrum and phononic properties of the quasi one-dimensional Severin aperiodic multilayer was investigated. Multilayer phononic structures with their phononic band gap properties can be used as filters of mechanical waves. In the paper, the implementation of the Finite Difference Time Domain (FDTD) algorithm with discrete Fourier transform and the Transfer Matrix Method algorithm in the Wolfram Language in Mathematica was made.
    Źródło:
    Journal of Applied Mathematics and Computational Mechanics; 2017, 16, 4; 17-27
    2299-9965
    Pojawia się w:
    Journal of Applied Mathematics and Computational Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    On the Interaction of Resonance And Bragg Scattering Effects for the Locally Resonant Phononic Crystal with Alternating Elastic and Fluid Matrices
    Autorzy:
    Yuan, B.
    Chen, Y.
    Jiang, M.
    Tang, S.
    He, M.
    Tu, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/177103.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    locally resonant phononic crystals
    effective speed of sound
    coupling band gaps
    underwater acoustic materials
    Opis:
    Three-dimensional (3D) locally resonant phononic crystals (LRPCs) are studied with the aim of optimising the sub-wavelength band gaps of such composites. By analysing their effective acoustic properties, it has been found that the effective acoustic speed of the composite will drop to zero when local resonance arise, and will increase monotonically when Bragg scattering effects occur. Moreover, if the matrix is a low-shear-speed medium, local resonators can significantly reduce the effective acoustic speed of the composite and, therefore, lower the frequency where Bragg scattering effects occur. Hence, a specific LRPC with alternating elastic and fluid matrices is proposed, whose resonance and Bragg gaps are already close in frequency. The fluid matrix behaves as a wave filter, which prevents the shear waves from propagating in the composite. By using the layer-multiple-scattering theory, the coupling behaviour of local resonance and Bragg scattering band gaps has been investigated. Both gaps are enhanced when they move closer to each other. Finally, a gap-coupled case is obtained that displays a broad sub-wavelength band gap. Such proposal excels at the application of underwater acoustic materials since the arrangement of structure can be handily adjusted for tuning the frequency of coupled gap.
    Źródło:
    Archives of Acoustics; 2017, 42, 4; 725-733
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Minimizing the number of layers of the quasi one-dimensional phononic structures
    Autorzy:
    Garus, Sebastian
    Sochacki, Wojciech
    Kubanek, Mariusz
    Nabiałek, Marcin
    Powiązania:
    https://bibliotekanauki.pl/articles/2173523.pdf
    Data publikacji:
    2022
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    mechanical waves
    phononic
    transfer matrix
    band gap
    genetic algorithm
    fale mechaniczne
    fononiczny
    macierz przejścia
    pasmo wzbronione
    algorytm genetyczny
    Opis:
    In the work, multi-criteria optimization of phononic structures was performed to minimize the transmission in the frequency range of acoustic waves, eliminate high transmission peaks with a small half-width inside of the band gap, and what was the most important part of the work – to minimize the number of layers in the structure. Two types of the genetic algorithm were compared in the study. The first one was characterized by a constant number of layers (GACL) of the phononic structure of each individual in each population. Then, the algorithm was run for a different number of layers, as a result of which the structures with the best value of the objective function were determined. In the second version of the algorithm, individuals in populations had a variable number of layers (GAVL) which required a different type of target function and crossover procedure. The transmission for quasi-one-dimensional phononic structures was determined with the use of the transfer matrix method algorithm. Based on the research, it can be concluded that the developed GAVL algorithm with an appropriately selected objective function achieved optimal solutions in a much smaller number of iterations than the GACL algorithm, and the value of the k parameter below 1 leads to faster achievement of the optimal structure.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 1; e139394, 1--8
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of spatial distribution and the type of material on the occurrence of bandgaps in phononic crystals
    Autorzy:
    Garus, Sebastian
    Sochacki, Wojciech
    Kwiatoń, Paweł
    Nabiałek, Marcin
    Petrů, Jana
    Kubanek, Mariusz
    Powiązania:
    https://bibliotekanauki.pl/articles/27311439.pdf
    Data publikacji:
    2023
    Wydawca:
    Polska Akademia Nauk. Czasopisma i Monografie PAN
    Tematy:
    finite difference time domain
    band gap
    phononic crystal
    mechanical waves
    propagation
    domena czasowa różnic skończonych
    kryształ fononiczny
    fale mechaniczne
    propagacja
    przerwa energetyczna
    Opis:
    The study investigated the effect of the fill factor, lattice constant, and the shape and type of meta-atom material on the reduction of mechanical wave transmission in quasi-two-dimensional phononic structures. A finite difference algorithm in the time domain was used for the analysis, and the obtained time series were converted into the frequency domain using the discrete Fourier transform. The use of materials with large differences in acoustic impedance allowed to determine the influence of the meta-atom material on the propagation of the mechanical wave.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 3; art. no. e144609
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    High-performance quasi one-dimensional mirrors of mechanical waves built of periodic and aperiodic structures
    Autorzy:
    Garus, S.
    Sochacki, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/122921.pdf
    Data publikacji:
    2018
    Wydawca:
    Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
    Tematy:
    mechanical waves
    phononic
    reflectance
    transfer matrix
    band gap
    fale mechaniczne
    struktura okresowa
    współczynnik odbicia
    macierz transferu
    pasmo wzbronione
    Opis:
    The work studied the reflectance for quasi one-dimensional phononical structures. In composite superlattices, the thickness of the layers, their arrangement and selection of constituent materials with appropriate properties such as the density and velocity of mechanical waves propagation allows for the creation of a phononic band gap (PhBG) phenomenon. PhBG is characterized by high reflectance of the mechanical wave incident on the analyzed structure, which means that the wave does not propagate in the superlattice. The paper proposes periodic and aperiodic structures characterized by a wide range of reflectance for the ultrasonic frequencies of mechanical waves and shows how the change the thickness of the layer affects the properties of the analyzed structures.
    Źródło:
    Journal of Applied Mathematics and Computational Mechanics; 2018, 17, 4; 19-24
    2299-9965
    Pojawia się w:
    Journal of Applied Mathematics and Computational Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Fluid-fluid phononic crystal with elastic coat working in audible frequencies
    Autorzy:
    Klimek, Aleksandra
    Powiązania:
    https://bibliotekanauki.pl/articles/128012.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Poznańska. Instytut Mechaniki Stosowanej
    Tematy:
    phononic crystals
    band gap
    Finite Element Method
    viscoelasticity
    kryształ fononiczny
    przerwa fotoniczna
    metoda elementów skończonych
    lepkosprężystość
    Opis:
    Phononic Crystals are receiving rising attention in the field of modern acoustic materials. PCs are artificial structures of periodically arranged scatterers. Such a structure enables creating a band gap in which, due to the Bragg diffraction phenomenon, vibrations are restrained or even forbidden. In this paperwork, the fluid-fluid PC is tested and simulated - the scatterers are constructed of water cylinders with an ethylene propylene diene monomer coat (EPDM - a hyperelastic rubber) and are embedded in air. The band gap is calculated to emerge in the audible range of frequency. Every simulation is performed with the use of the finite element method.
    Źródło:
    Vibrations in Physical Systems; 2019, 30, 1; 1-7
    0860-6897
    Pojawia się w:
    Vibrations in Physical Systems
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effective properties of periodic media in elastodynamic problems
    Autorzy:
    Yera, Rolando
    Méndez, Carlos G.
    Sánchez, Pablo J.
    Huespe, Alfredo E.
    Powiązania:
    https://bibliotekanauki.pl/articles/29520225.pdf
    Data publikacji:
    2021
    Wydawca:
    Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
    Tematy:
    effective properties
    acoustic metamaterials
    wave propagation
    periodic media
    Bloch waves
    phononic crystal
    metamateriały akustyczne
    propagacja fali
    media okresowe
    fale Blocha
    kryształ fononiczny
    Opis:
    This paper describes a homogenization model for evaluating the effective elastodynamic properties of acoustic metamaterials in problems involving wave propagation. The methodology is based on determining the constitutive equations in terms of averaged quantities observed at the macroscale. In this sense, the approach very closely follows the pioneering ideas introduced by Willis, and afterwards, followed by several authors in the last ten years. The distinctive characteristic of our approach is that we write the microscale equation in the spatial domain. The model is validated with previous results published in the literature, and our results replicate them almost exactly. The resulting homogenization model could be used as an additional tool for the topology design of acoustic metamaterials.
    Źródło:
    Computer Methods in Materials Science; 2021, 21, 3; 139-148
    2720-4081
    2720-3948
    Pojawia się w:
    Computer Methods in Materials Science
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Design, Manufacture and Characterization of an Acoustic Barrier Made of Multi-Phenomena Cylindrical Scatterers Arranged in a Fractal-Based Geometry
    Autorzy:
    Casteneira-Ibanez, S.
    Rubio, C.
    Romero-Garcia, V.
    Sanchez-Perez, J. V.
    Garcia-Raffi, L. M.
    Powiązania:
    https://bibliotekanauki.pl/articles/176662.pdf
    Data publikacji:
    2012
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    acoustic arrays
    acoustic attenuation
    acoustic wave absorption
    acoustic wave scattering
    phononic crystals
    acoustic barrier
    physical effect of sound
    Opis:
    In this work we present the design and the manufacturing processes, as well as the acoustics standard- ization tests, of an acoustic barrier formed by a set of multi-phenomena cylindrical scatterers. Periodic arrangements of acoustic scatterers embedded in a fluid medium with different physical properties are usually called Sonic Crystals. The multiple scattering of waves inside these structures leads to attenuation bands related to the periodicity of the structure by means of Bragg scattering. In order to design the acoustic barrier, two strategies have been used: First, the arrangement of scatterers is based on fractal geometries to maximize the Bragg scattering; second, multi-phenomena scatterers with several noise con- trol mechanisms, as resonances or absorption, are designed and used to construct the periodic array. The acoustic barrier reported in this work provides a high technological solution in the field of noise control.
    Źródło:
    Archives of Acoustics; 2012, 37, 4; 455-462
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Bandgap properties in locally resonant phononic crystal double panel structures with periodically attached pillars
    Autorzy:
    Qian, D.
    Shi, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/280927.pdf
    Data publikacji:
    2017
    Wydawca:
    Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
    Tematy:
    bandgap property
    phononic crystal double panel
    band structure
    displacement field
    transmission power spectrum
    Opis:
    The locally resonant (LR) phononic crystal double panel structure made of a two-dimensional periodic array of a two-component cylindrical LR pillar connected between the upper and lower plates is proposed, and the bandgap properties of the structure are investigated theoretically in this paper. The band structures, displacement fields of eigenmodes and transmission power spectrums of the corresponding 8×8 finite structure are calculated by the finite element method. Numerical results and further analysis demonstrate that a band gap with a low starting frequency and a wide band width is opened by the coupling between dominant vibrations of the pillars and plate modes of the upper and lower plates when the vibration source and the receiver are considered on different sides of the structure. By comparing the band structures and displacement fields of the double panel and those of the single plate with the same parameters, many common characteristics are displayed. Then, the influence of geometrical parameters on the band gap are studied and understood with the help of a simple ‘spring-mass’ model.
    Źródło:
    Journal of Theoretical and Applied Mechanics; 2017, 55, 4; 1167-1179
    1429-2955
    Pojawia się w:
    Journal of Theoretical and Applied Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A Honeycomb Based Graded Metamaterial Muffler with Broadband Sound Attenuation and Load Bearing Performances
    Autorzy:
    Li, Gen
    Chen, Yan
    He, Huan
    Powiązania:
    https://bibliotekanauki.pl/articles/2141654.pdf
    Data publikacji:
    2022
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    acoustic metamaterials
    honeycomb structure
    phononic crystal
    local resonance
    Opis:
    A challenge for developing acoustic metamaterials (AMMs) is considering the application of broadband muffling and load bearing capacity simultaneously. In this paper, a honeycomb based graded AMM muffler is proposed, which can widen the attenuation band and improve the structural stiffness without any external device by means of integrated design. Firstly, the acoustic and mechanical characteristics of the muffler unit cell are theoretically and numerically studied, and the graded muffler is designed based on these characteristics. The numerical results show that the graded muffler widens the attenuation bandwidth of the unit cell, and the simulation also shows that the graded muffler has greater stiffness than the uniform one. The stiffness driven muffler provides new possibilities for the design of advanced metamaterial with simultaneous sound insulation and load bearing performances.
    Źródło:
    Archives of Acoustics; 2022, 47, 2; 213-221
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
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