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Wyszukujesz frazę "stiffness matrix method" wg kryterium: Temat


Wyświetlanie 1-7 z 7
Tytuł:
An application of stiffness matrix method to determining of dispersion curves for arbitrary composite materials
Autorzy:
Barski, M.
Pająk, P.
Powiązania:
https://bibliotekanauki.pl/articles/244021.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
SHM system
multi-layered composites
elastic waves
dispersion curves
stiffness matrix method
Opis:
Nowadays multi-layered composite material is very often applied in different kind of structures, like aircrafts, boats or vehicles. Parts of structures, which are made of these materials, are significantly lighter in comparison with traditional materials, like aluminum or steel alloys. On the other hand, the process of damage creation and evolution in the case of composites is much more complex. Moreover, the damages, which are characteristic for multi-layered materials (matrix cracking, fibre breakage, delaminations), are very difficult to detect at early stage of creation. Hence, there is a need to develop the advanced methods to detect them without destroying tested composite element. One of them is based on analysis of elastic wave propagation through the composite structure. Unfortunately, elastic waves possess strongly dispersive character. Thus, it is necessary to determine dispersion curves for investigated material before the tests in order to appropriate interpretation of received dynamic response of structure. In the case of arbitrary composite materials, it is rather challenging task. In the present article the relatively new, analytical method is applied, namely stiffness matrix method. The fundamental assumptions and the theoretical formulation of this method are discussed. Next numerical examples are presented, namely the dispersion curves are determined for the single orthotropic lamina and multi-layered 'quasi - isotropic' composite plate. The studied plates are made of glass fibres and epoxy resin. In the case of single lamina, the dispersion curves are determined in the parallel, perpendicular and arbitrary direction of waves propagation with respect to the fibre direction. In the case of multi-layered plates, the dispersion curves are computed for one arbitrary direction. Additionally, the phase and group velocities for fundamental modes and fixed excitation frequency are estimated in all directions of waves propagation.
Źródło:
Journal of KONES; 2016, 23, 1; 47-54
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of dispersion curves for composite materials with the use of stiffness matrix method
Autorzy:
Barski, M.
Pająk, P.
Powiązania:
https://bibliotekanauki.pl/articles/386825.pdf
Data publikacji:
2017
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
structural health monitoring
layered composite materials
guided waves
dispersion curves
stiffness matrix method
Opis:
Elastic waves used in Structural Health Monitoring systems have strongly dispersive character. Therefore it is necessary to determine the appropriate dispersion curves in order to proper interpretation of a received dynamic response of an analyzed structure. The shape of dispersion curves as well as number of wave modes depends on mechanical properties of layers and frequency of an excited signal. In the current work, the relatively new approach is utilized, namely stiffness matrix method. In contrast to transfer matrix method or global matrix method, this algorithm is considered as numerically unconditionally stable and as effective as transfer matrix approach. However, it will be demonstrated that in the case of hybrid composites, where mechanical properties of particular layers differ significantly, obtaining results could be difficult. The theoretical relationships are presented for the composite plate of arbitrary stacking sequence and arbitrary direction of elastic waves propagation. As a numerical example, the dispersion curves are estimated for the lamina, which is made of carbon fibers and epoxy resin. It is assumed that elastic waves travel in the parallel, perpendicular and arbitrary direction to the fibers in lamina. Next, the dispersion curves are determined for the following laminate [0°, 90°, 0°, 90°, 0°, 90°, 0°, 90°] and hybrid [Al, 90°, 0°, 90°, 0°, 90°, 0°], where Al is the aluminum alloy PA38 and the rest of layers are made of carbon fibers and epoxy resin.
Źródło:
Acta Mechanica et Automatica; 2017, 11, 2; 121-128
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of the configuration of the fiber-metal laminates on the dispersion relations of the elastic wave modes
Autorzy:
Barski, Marek
Muc, Aleksander
Stawiarski, Adam
Powiązania:
https://bibliotekanauki.pl/articles/2146565.pdf
Data publikacji:
2020
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
FML
fiber metal laminates
GLARE
elastic wave modes
dispersion curves
stiffness matrix method
laminaty metalowo-włókniste
mody fal sprężystych
krzywa dyspersji
metoda macierzy sztywności
Opis:
The current work is devoted to the determination of dispersion curves for elastic wave modes. The studied elastic waves propagate across metal-fiber hybrid composites. In order to solve the problem, special software has been developed with the use of C++. This software works with the MS Windows operating system and the proposed solution is based on the multi-threading mechanism. It makes possible to significantly speed up the calculations. The relatively new approach is used namely the stiffness matrix method. At the very beginning, the dispersion curves are determined for the traditional composite materials of cross-ply configuration, for which the layers are made of glass fiber/epoxy resin and carbon fiber/epoxy resin. The impact of the total number of layers on the dispersion curves is investigated. Next, the influence of the thickness of the layers, which are made of aluminum alloy, on the dispersion characteristic is studied. In the second case, it is assumed that the total thickness of the composite material wall for all cases is identical.
Źródło:
Vibrations in Physical Systems; 2020, 31, 2; art. no. 2020202
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical and numerical identification of lamb waves modes for hybrid composites
Autorzy:
Barski, M.
Pająk, P.
Powiązania:
https://bibliotekanauki.pl/articles/245066.pdf
Data publikacji:
2017
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
structural health monitoring
elastic waves
dispersion curve
stiffness matrix method
numerical simulations
finite element method
group velocity
fale sprężyste
krzywa dyspersji
symulacje numeryczne
metoda elementów skończonych
prędkość grupowa
Opis:
The current work is devoted to the problem of analytical and numerical identification of fundamental elastic waves' modes, namely symmetric mode S0 and antisymmetric mode A0, in the case of hybrid composite. The investigated material consists of one layer made of aluminum alloy Pa38 and six layers made of glass fabric/epoxy resin. At the very beginning, the dispersion curves are determined with the use of stiffness matrix method. The calculated values of phase velocities are verified by numerical simulation. The semi – analytical finite element method is applied. Next, the numerical simulations of elastic waves propagation are performed. In the studied model, the plane state of strain is assumed. These simulations are carried out with the use of finite element method. The excitation signal is a sine wave modulated by Hanning window. The simulation is repeated for different excitation frequency. The group velocities of wave modes S0 and A0 are estimated and compared with the analytical results. The evaluation of the group velocities is based on the analysis of the appropriate components of displacement. The two different method are employed, namely: cross – correlation method and envelope extraction by Hilbert transform. Generally, the obtained results are in a good agreement. However, the method based on envelope extraction by Hilbert transform provides better correlation between analytical and numerical results. The significant discrepancy is observed in the case of symmetric mode S0 for relatively high values of frequency. It is caused by the dispersion phenomena. The analytical calculations are performed with the use of SCILAB 5.5.2 free software and the numerical simulations are carried out with the use of finite element system ANSYS 13.0.
Źródło:
Journal of KONES; 2017, 24, 1; 31-38
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Torsion of restrained thin-walled bars of open constant bisymmetric cross-section
Autorzy:
Kujawa, M.
Powiązania:
https://bibliotekanauki.pl/articles/1933993.pdf
Data publikacji:
2012
Wydawca:
Politechnika Gdańska
Tematy:
thin-walled bars
elastic stiffness matrix
geometric stiffness matrix
restrained torsion
Castigliano’s method
torsional buckling
Opis:
Elastic and geometric stiffness matrices were derived using Castigliano’s first theorem, for the case of torsion of restrained thin-walled bars of open constant bisymmetric cross-section. Functions which describe the angles of torsion were adopted from the solutions of the differential equation for restrained torsion. The exact solutions were simplified by expanding them in a power series. Numerical examples were taken from Kujawa M 2009 Static and Sensitivity Analysis of Grids. . . 97, GUT Publishing House, and Szymczak C 1978 Engineering Transaction 26 323. Convergence of the solutions was analyzed using the matrices derived for torsion angles, warping, bimoments and critical forces.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2012, 16, 1-2; 5-15
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Behavior and failure tracking of structural elements using applied element method
Autorzy:
Badawy, Mahmoud Mohamed
Mustafa, Suzan Ali A.
Bakry, Atef Eraky
Powiązania:
https://bibliotekanauki.pl/articles/35561246.pdf
Data publikacji:
2022
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
applied element method
AEM
numerical analysis
stiffness matrix
large deformation failure tracking
Opis:
Applied element method (AEM) is a recently displacement-based structural analysis method. It provides the benefits of both the finite element method (FEM) and the discrete element method (DEM). This method relies on those structures are segmented into rigid elements linked by normal and shear springs. In this paper a brief note of the AEM is given. Then, using the AEM, a 2D MATLAB open source program was created to analyze different structures with varied boundary conditions and to permit researchers for enhancing the method. The proposed program was verified using linear elastic analysis and large deformation static analysis. The influence of element size and the number of connecting springs between elements was studied. Finally, the proposed program was capable of tracking failed elements and their spread. In addition, the program could predict deflection values and structure deformed shape.
Źródło:
Scientific Review Engineering and Environmental Sciences; 2022, 31, 3; 203-222
1732-9353
Pojawia się w:
Scientific Review Engineering and Environmental Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Distorsional analysis of I-section beam
Autorzy:
Kujawa, M.
Powiązania:
https://bibliotekanauki.pl/articles/1933992.pdf
Data publikacji:
2012
Wydawca:
Politechnika Gdańska
Tematy:
distortion
thin-walled I-section beam
elastic stiffness matrix
energetic approach
Castigliano’s method
Opis:
An elastic stiffness matrix was derived in the case of distortion of a restrained thin- walled I-section beam using the minimum total stationary elastic energy condition (Przemie- niecki J S 1968 Theory of Matrix Structural Analysis, McGraw-Hill, NY). The function describ- ing the angle of distortion was adopted form the solution of differential equation in the case of restrained distortion. The example presented in the paper helps to assess the correctness of the proposed solution. The proposed elastic stiffness matrix is applicable for solving distortion problems of bar structures composed of thin-walled members.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2012, 16, 1-2; 17-22
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-7 z 7

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