Wszystkie pola: acoustic method

Skocz do pozycji: 1.

Tytuł:: Investigation of orthopedic constructions fracture using CAE technologies and the acoustic emission method
Autorzy:: Stankevych, Olena
Zdobytskyi, Andrii
Tematy:: orthopedic dentistry
finite element method
acoustic emission
wavelet transform
endocrown; Pokaż więcej
Wydawca:: Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Powiązania:: https://bibliotekanauki.pl/chapters/60016635.pdf Link otwiera się w nowym oknie
Opis:: The use of CAE systems in the known calculations showed the effectiveness and advantages of using endocrown structures for tooth restoration. A methodology for investigating the fracture dynamics of fixed dental orthopedic structures using the acoustic emission method has been developed. Based on the multi-parameter analysis of AE signals and the results of stress distribution modeling of the tooth-endocrown system, it was established that the fracture starts in the tooth root. The metal-ceramic endocrown restoration had the highest fracture resistance.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Innovative acoustic emission method for monitoring the quality and integrity of ferritic steel gas pipelines
Autorzy:: Świt, Grzegorz
Ulewicz, Małgorzata
Pała, Robert
Adamczak-Bugno, Anna
Lipiec, Sebastian
Krampikowska, Aleksandra
Dzioba, Ihor
Tematy:: Pipelines
finite element method
Stress
Strain
Acoustic Emission Method
rurociągi
metoda elementów skończonych
stres
napięcie
metoda emisji akustycznej; Pokaż więcej
Wydawca:: Stowarzyszenie Menedżerów Jakości i Produkcji
Powiązania:: https://bibliotekanauki.pl/articles/59122794.pdf Link otwiera się w nowym oknie
Opis:: This article presents a comprehensive improvement in the experimental analysis of cracking processes in smooth and sharp V-notched samples taken from gas transport pipelines, utilizing the acoustic emission (AE) method. The research aimed to establish a robust correlation between the failure mechanisms of uniaxially tensile samples and the distinct characteristics of AE signals for enhanced quality management in pipeline integrity. The study encompassed materials from two different straight pipe sections, encompassing both long-term used materials and new, unused materials. Through the application of the k-means grouping method to AE signal analysis, we achieved the identification of AE signal parameters characteristic of various stages of the material destruction process. This advancement introduces a significant improvement in monitoring and managing the operational safety of pipeline networks, offering a methodology that leverages advanced acoustic emission signal analysis. The outcomes present significant implications for the pipeline industry by proposing methods to enhance safety systems and more effectively manage the integrity and quality of gas infrastructure.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Numerical modeling of transient acoustic field using finite element method
Autorzy:: Koudela, L.
Jansa, J.
Karban, P.
Tematy:: acoustic field
finite element method
acoustic wave; Pokaż więcej
Wydawca:: Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Powiązania:: https://bibliotekanauki.pl/articles/377945.pdf Link otwiera się w nowym oknie
Opis:: Numerical solution of acoustic wave equation in the time domain is performed. The appropriate mathematical model is described by the partial differential wave equation supplemented with appropriate boundary conditions. The goal is to obtain the time evolution of the distribution of acoustic pressure, which can serve as the basis for the solution of various subsequent problems. The paper discusses the results of the numerical analysis of a semicircular acoustic diffuser in a free field, realized by a fully adaptive higher-order finite element method implemented in our own codes Agros2D and Hermes. The results are compared with the data obtained by the commercial code Comsol Multiphysics.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: A Coupled Smoothed Finite Element-Boundary Element Method for Structural-Acoustic Analysis of Shell
Autorzy:: Tian, W.
Yao, L.
Li, L.
Tematy:: SFEM
smoothed finite element method
FEM
finite element method
BEM
boundary element method
structural-acoustic analysis; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/177260.pdf Link otwiera się w nowym oknie
Opis:: Nowadays, the finite element method (FEM) – boundary element method (BEM) is used to predict the performance of structural-acoustic problem, i.e. the frequency response analysis, modal analysis. The accuracy of conventional FEM/BEM for structural-acoustic problems strongly depends on the size of the mesh, element quality, etc. As element size gets greater and distortion gets severer, the deviation of high frequency problem is also clear. In order to improve the accuracy of structural-acoustic problem, a smoothed finite-element/boundary-element coupling procedure (SFEM/BEM) is extended to analyze the structural-acoustic problem consisting of a shell structure interacting with the cavity in this paper, in which the SFEM and boundary element method (BEM) models are used to simulate the structure and the fluid, respectively. The governing equations of the structural-acoustic problems are established by coupling the SFEM for the structure and the BEM for the fluid. The solutions of SFEM are often found to be much more accurate than those of the FEM model. Based on its attractive features, it was decided in the present work to extend SFEM further for use in structural-acoustic analysis by coupling it with BEM, the present SFEM/BEM is implemented to predict the vehicle structure-acoustic frequency response analysis, and two numerical experiments results show that the present method can provide more accurate results compared with the standard FEM/BEM using the same mesh. It indicates that the present SFEM/BEM can be widely applied to solving many engineering noise, vibration and harshness (NVH) problems with more accurate solutions.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Limitations in application of Finite Element Method in acoustic numerical simulation
Ograniczenia zastosowania Metody Elementów Skończonych w analizie numerycznej pola akustycznego
Autorzy:: Łodygowski, T.
Sumelka, W.
Tematy:: pole akustyczne
metoda elementów skończonych
applied acoustics
finite element method; Pokaż więcej
Wydawca:: Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Powiązania:: https://bibliotekanauki.pl/articles/280686.pdf Link otwiera się w nowym oknie
Opis:: In the paper, we introduce information on limitations of the Finite Element Method in acoustic analysis. Difficulties that appear in acoustic analysis are mainly caused by the form of shape functions and sensitivities to boundaries, so we start with a short description of mathematical background. The propositions how to overcome and simplify those disadvantages are summarized and illustrated with a real application.
W pracy przedstawiono ograniczenia zastosowania Metody Elementów Skończonych w analizie numerycznej pola akustycznego. Wykazano, iż trudności w ocenie rozkładu akustycznych pól ciśnień spowodowane są doborem funkcji kształtu, wrażliwością na warunki brzegowe oraz gęstością stosowanych siatek MES. Na bazie porównania symulacji numerycznych z przeprowadzonym eksperymentem pokazano, w jaki sposób można niektóre z tych ograniczeń pominąć oraz do jakiego stopnia można uprościć analizę akustyczną, przyjmując modele dwuwymiarowe.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Harmonical and modal analysis to determine the anisotropic properties of aviation composite materials
Autorzy:: Acopyan, A.
Axenov, V.
Shevtsov, V.
Soloviev, A.
Tamarkina, E.
Tematy:: polymeric composite
elastic module
acoustic measurements
eigenmodes
finite element method; Pokaż więcej
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Powiązania:: https://bibliotekanauki.pl/articles/243138.pdf Link otwiera się w nowym oknie
Opis:: The value of all composite elastic modules has the crucial influence on dynamic behaviour of aviation load-bearing structures. Numerous experimental techniques and standards are used to characterize the elastic properties of polymeric composite materials. Among this is the large group of static tests, acoustic methods based on longitudinal, lateral or shear surface sound wave speed measurements and also on vibrating surfaces amplitude measurements. However, preparation specimens for static test with shape required by standards not always possible from already manufactured piece. Again the designated dynamic experiment introduces difficulties of investigated specimen acoustic isolating, impossibility of some required wave type excitation and performing of displacements field measurement with guaranteed precision. In this study an acoustic method is developed using the measure of all specimen's eigenfrequencies in a certain frequency range. Small rectangular composite specimen is excited by glued piezoelectric actuator and response is measured by piezoelectric sensor. Preliminary performed finite-element (FE) analyses serve to think the vibration natural modes of linked mechanical system - specimen and piezoelectric element. In this FE analyse the rough estimations of all elastic constants obtained from other independents (as a rule static) experiments were used. Further the amelioration of initial elastic modules was performed. Thereby the target nonlinear functional dependent on all quest modules was minimized by genetic and (or) Levenberg-Marquardt algorithm.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: 2D Structural Acoustic Analysis Using the FEM/FMBEM with Different Coupled Element Types
Autorzy:: Chen, L.
Zhao, W.
Liu, C.
Chen, H.
Tematy:: boundary element method
finite element method
discontinuous boundary elements
acoustic fluid-structure interaction
fast multipole method; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/176330.pdf Link otwiera się w nowym oknie
Opis:: A FEM-BEM coupling approach is used for acoustic fluid-structure interaction analysis. The FEM is used to model the structure and the BEM is used to model the exterior acoustic domain. The aim of this work is to improve the computational efficiency and accuracy of the conventional FEM-BEM coupling approach. The fast multipole method (FMM) is applied to accelerating the matrix-vector products in BEM. The Burton-Miller formulation is used to overcome the fictitious eigen-frequency problem when using a single Helmholtz boundary integral equation for exterior acoustic problems. The continuous higher order boundary elements and discontinuous higher order boundary elements for 2D problem are developed in this work to achieve higher accuracy in the coupling analysis. The performance for coupled element types is compared via a simple example with analytical solution, and the optimal element type is obtained. Numerical examples are presented to show the relative errors of different coupled element types.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Numerical modeling of Gauss monocycle pulse in transient acoustic field
Autorzy:: Koudela, L.
Jansa, J.
Karban, P.
Tematy:: Gauss monocycle pulse
acoustic transient field
finite element method; Pokaż więcej
Wydawca:: Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Powiązania:: https://bibliotekanauki.pl/articles/97307.pdf Link otwiera się w nowym oknie
Opis:: Numerical solution of acoustic wave equation in the time domain is performed. The mathematical model is described by the partial differential wave equation supplemented with appropriate boundary conditions. The goal is to obtain the time evolution of the distribution of acoustic pressure, which can serve as the basis for the solution of various subsequent problems. The paper discusses the results of the numerical analysis of the Gauss monocycle pulse that proceeds from the signal source and incident on the semi-circular acoustic diffuser in a free field, realized by a fully adaptive higherorder finite element method implemented in codes Agros2D and Hermes developed by the hp-FEM group. Selected results of the computations are compared with the data obtained by the commercial code COMSOL Multiphysics.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Acoustic Simulation’s Verification of WFI ATHENA Filterwheel Assembly
Autorzy:: Pilch, A.
Kamisiński, T.
Rataj, M.
Polak, S.
Tematy:: filterwheel mechanism
FEM
finite element method
FEM acoustic analysis
ATHENA mission
WFI
Wide Filed Imager; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/176723.pdf Link otwiera się w nowym oknie
Opis:: Ariane 5 rocket produces very high sound pressure levels during launch, what can influence structures located in the fairing. To reduce risk of damage, launch in vacuum conditions is preferred for noise sensitive instruments. In Wide Filed Imager (WFI) project, the main part of the filterwheel assembly is an extremely thin (~240 nm) filter of large area (170×170 mm), very sensitive to noise and vibrations. The aim of this study was to verify numerical calculations results in anechoic measurements. The authors also checked the influence of WFI geometry and sound absorbing material position on sound pressure level (SPL) affecting the filter mounted inside the assembly. Finite element method (FEM) simulations were conducted in order to obtain noise levels in filter position during Ariane 5 rocket launch. The results will be used in designing of WFI filterwheel assembly and endurance of the filter during launch verification.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: The Effect of the Cavity Damping on Vehicular Evaluation using the Finite Element Method
Autorzy:: Ferreira, T. S.
Magalhães, P. A.
Moura, F. L.
Tematy:: finite element method
acoustic control
trimmed body
numerical experimental correlation
modal damping; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/176986.pdf Link otwiera się w nowym oknie
Opis:: This work focuses on finding a numerical solution for vehicle acoustic studies and improving the usefulness of the numerical experimental parameters for the development stage of a new automotive project. Specifically, this research addresses the importance of modal cavity damping for vehicle exerts during numerical studies. It then seeks to suggest standardized parameter values of modal cavity damping in vehicular acoustic studies. The standardized value of modal cavity damping is of great importance for the study of vehicular acoustics in the automotive industry because it would allow the industry to begin studies of the acoustic performance of a new vehicle early in the conception phase with a reliable estimation that would be close to the final value measured in the design phase. It is common for the automotive industry to achieve good levels of numerical-experimental correlation in acoustic studies after the prototyping phase because this phase can be studied with feedback from the simulation and experimental modal parameters. Thus, this research suggests values for modal cavity damping, which are divided into two parts due to their behaviour: ξ(x) = −0.0126(x − 100) + 6.15 as a variable function to analyse up to 100 Hz and 6.15% of modal cavity damping constant for studies between 30 Hz and 100 Hz. The sequence of this study shows how we arrived at these values.
Dostawca treści:: Biblioteka Nauki

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