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Tytuł:
Free vibration analysis of FGM stepped nanostructures using nonlocal dynamic stiffness model
Autorzy:
Lien, Tran Van
Duc, Ngo Trong
Dinh, Tran Binh
Dat, Pham Tuan
Powiązania:
https://bibliotekanauki.pl/articles/2086972.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
nonlocal
DSM
FGM
nanostructure
nondimensional frequency
Opis:
A nonlocal Dynamic Stiffness Model (DSM) for free vibration analysis of Functionally Graded Material (FGM) stepped nanostructures based on the Nonlocal Elastic Theory (NET) is proposed. An exact solution to the equation of motion of a nanobeam element according to the Timoshenko beam theory, NET, and taking into account position of the neutral axis is constructed. Nondimensional frequencies and mode shapes of complete FGM stepped nanostructures are easily obtained using the nonlocal DSM. Numerical results are presented to show significance of the material distribution profile, nonlocal effect, and boundary conditions on free vibration of nanostructures.
Źródło:
Journal of Theoretical and Applied Mechanics; 2022, 60, 2; 279--292
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical and numerical free vibration analysis of porous functionally graded materials (FGPMs) sandwich plate using Rayleigh-Ritz method
Autorzy:
Njim, E.K.
Bakhy, S.H.
Al-Waily, M.
Powiązania:
https://bibliotekanauki.pl/articles/2175769.pdf
Data publikacji:
2021
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
FGM sandwich plate
porosity parameter
CPT
free vibration
FEA
płyta warstwowa FGM
parametr porowatości
drgania swobodne
Opis:
Purpose: This study introduces a new approximated analytical solution of the free vibration analysis to evaluate the natural frequencies of functionally graded rectangular sandwich plates with porosities. Design/methodology/approach: The kinematic relations are developed based on the classical plate theory (CPT), and the governing differential equation is derived by employing the Rayleigh-Ritz approximate method. The FGM plate is assumed made of an isotropic material that has an even distribution of porosities. The materials properties varying smoothly in the thickness direction only according to the power-law scheme. Findings: The influences of changing the gradient index, porosity distribution, boundary conditions, and geometrical properties on the free vibration characteristics of functionally graded sandwich plates are analysed. Research limitations/implications: A detailed numerical investigation is carried out using the finite element method with the help of ANSYS 2020 R2 software to validate the results of the proposed analytical solution. Originality/value: The results with different boundary conditions show the influence of porosity distribution on the free vibration characteristics of FG sandwich plates. The results indicated a good agreement between the approximated method such as the Rayleigh-Ritz and the finite element method with an error percentage of no more than 5%.
Źródło:
Archives of Materials Science and Engineering; 2021, 110, 1; 27--41
1897-2764
Pojawia się w:
Archives of Materials Science and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bending, buckling and free vibration of a beam with unsymmetrically varying mechanical properties
Autorzy:
Magnucki, K.
Lewiński, J.
Magnucka-Blandzi, E.
Kędzia, P.
Powiązania:
https://bibliotekanauki.pl/articles/279585.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
FGM beam
mathematical modelling
numerical FEM calculations
Opis:
The subject of the paper is a beam with unsymmetrically varying mechanical properties in the depth direction. The nonlinear hypothesis of plane cross section deformation is assumed. Based on Hamilton’s principle, two differential equations of motion are obtained. The system of equations is analytically solved with a view to analyse the bending, buckling and free vibration problems of the beam. Moreover, the FEM model of the beam is developed and deflections, critical axial forces and natural frequencies of the beam are calculated. The results of these two methods are compared.
Źródło:
Journal of Theoretical and Applied Mechanics; 2018, 56, 4; 1163-1178
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On axisymmetric heat conduction problem for multilayer graded coated half-space
Autorzy:
Perkowski, D. M.
Kulchytsky-Zhyhailo, R.
Kołodziejczyk, W.
Powiązania:
https://bibliotekanauki.pl/articles/281629.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
temperature
heat flux
FGM
composite
homogenized model
Opis:
The technique of integral Hankel transform to find the solution of heat conduction in half-space coated by a multilayered package of homogenous laminae is applied. The half-space is heated by the given heat flux on the boundary surface. The temperature and heat flux distribution in the radial direction is analyzed for two types of coatings: 1) when the heat conductivity coefficient is described by a power or exponential function of the distance to the boundary surface; 2) multilayered coating has a periodic structure.
Źródło:
Journal of Theoretical and Applied Mechanics; 2018, 56, 1; 147-156
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the fibres shape effect on the temperature field in the two-phase hollow cylinder
Autorzy:
Ostrowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/362631.pdf
Data publikacji:
2010
Wydawca:
Instytut Fizyki Budowli Katarzyna i Piotr Klemm
Tematy:
przewodzenie ciepła
FGM
kompozyt
heat conduction
composite
Opis:
The unidirectional stationary heat conduction in two-phase hollow cylinder is considered. The conductor is made of two-phase stratified composites and has, in special cases, asmooth gradation of effective properties in the radial direction. Therefore, we deal here with a special case of functionally graded materials, FGM (cf. [6]). The formulation of mathematical model of the conductor is based on the tolerance averaging approach (TAA), cf. [8]. Application to the stationary heat conduction and a comparison of tolerance model with asymptotic model (cf. [7]) will be shown. The effect of fibres shape and width on the temperature field will be examined.
Źródło:
Fizyka Budowli w Teorii i Praktyce; 2010, T. 5, nr 3, 3; 45-48
1734-4891
Pojawia się w:
Fizyka Budowli w Teorii i Praktyce
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nieliniowe zagadnienie stacjonarnego przepływu ciepła w dwuskładnikowym przewodniku cylindrycznym
On the non-linear stationary heat conduction in two-phase hollow cylinder
Autorzy:
Ostrowski, P
Powiązania:
https://bibliotekanauki.pl/articles/362637.pdf
Data publikacji:
2011
Wydawca:
Instytut Fizyki Budowli Katarzyna i Piotr Klemm
Tematy:
przepływ ciepła
FGM
kompozyt
heat conduction
composite
Opis:
Celem pracy jest analiza nieliniowego stacjonarnego i jednokierunkowego przepływu ciepła w przewodniku cylindrycznym o funkcyjnie zmiennych własnościach efektywnych. Rozważany przewodnik na poziomie mikro składa się z dwufazowych komórek (pierścieni) o stałej szerokości, który przy dostatecznie dużej liczbie komórek można traktować jako materiał o funkcyjnej gradacji własności, FGM (por. [6]). Na brzegi przewodnika została narzucona stała po obwodzie temperatura, a współczynnik przewodzenia ciepła poszczególnych składników zamodelowano wielomianem pierwszego stopnia. Analizie poddano wpływ nieliniowości i rozkładu poszczególnych składników kompozytu na przebieg pola temperatury.
The main aim is to consider non-linear stationary and unidirectional heat conduction in a hollow cylinder with functionally graded effective material properties. The conductor is made of two-phase stratified cells (annuli) with constant width, which can he treated as a functionally graded material, FGM (cf. [6]) for a sufficient large number of cells. On the composite boundaries temperature is given, and conductivity coefficients are expressed by first degree polynomial. An effect of nonlinearity and component distribution on the temperature field.
Źródło:
Fizyka Budowli w Teorii i Praktyce; 2011, T. 6, nr 2, 2; 83-85
1734-4891
Pojawia się w:
Fizyka Budowli w Teorii i Praktyce
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical creep analysis of FGM rotating disc with GDQ method
Autorzy:
Zharfi, H.
Toussi, H. E.
Powiązania:
https://bibliotekanauki.pl/articles/280599.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
creep
FGM
GDQ method
rotating disc
boundary conditions
Opis:
Rotating discs are the vital part of many kinds of machineries. Usually, they are operating at relatively high angular velocity and temperature conditions. Accordingly, in practice, the creep analysis is an essential necessity in the study of rotating discs. In this paper, the time dependent creep analysis of a thin Functionally Graded Material (FGM) rotating disc investigated using the Generalized Differential Quadrature (GDQ) method. Creep is described with Sherby’s constitutive model. Secondary creep governing equations are derived and solved for a disc with two various boundary conditions and with linear distribution of SiC particles in pure Aluminum matrix. Since the creep rates are a function of stresses, time and temperature, there is not a closed form solution to these equations. Using a solution algorithm and the GDQ method, a solution procedure for these nonlinear equations is presented. Comparison of the results with other existing creep studies in literature reveals the robustness, precision and high efficiency beside rapid convergence of the present approach.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 1; 331-341
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Piezoelectric effect on thermoelastic Lamb waves in functionally graded plates
Autorzy:
Wang, X.
Ren, X.
Yu, J.
Zhou, H.
Zhang, X.
Leng, J
Powiązania:
https://bibliotekanauki.pl/articles/38695708.pdf
Data publikacji:
2023
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
thermoelastic wave
attenuation
FGM
piezoelectric effect
physical field distributions
Opis:
Based on the Lord–Shulman thermoelectric elasticity theory, the piezoelectric effect on the thermoelastic Lamb wave propagation in the functionally graded material (FGM) plate is investigated. The coupled wave equations are solved by employing the Legendre polynomial series approach (LSPA), which poses the advantages of small scale of eigenvalues matrix and a convenient solution. It can directly obtain the complex wave number solutions without iteration. The obtained complex solutions, which represent the wave propagation and attenuation, are compared with those available data. Numerical examples show that the influence of gradient is profound. Results indicate that the piezoelectric effects on attenuation with the open and closed circuit condition are consistent for the S0 and S1 modes, but are inconsistent for the A0 and A1 modes. Although the piezoelectric effect is weak on the dispersion and attenuation of thermal waves, it is notable for their physical field distributions. In addition, the relaxation time is critical to electric displacements of a thermal wave mode, but is not essential for those of Lamb-like modes. The results can be used for the optimization of thermo-electric-elastic coupling structures.
Źródło:
Archives of Mechanics; 2023, 75, 1-2; 3-26
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of FGM plates
Autorzy:
Jemielita, G.
Kozyra, Z.
Powiązania:
https://bibliotekanauki.pl/articles/280423.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
modelling
layer plate
FGM plate
stiffness of the plate
Opis:
The paper presents formulation of the problem of layered plates composed of two various isotropic materials. We assume that the first material M₁ is characterized by the following parameters: Young’s modulus E₁ and Poisson’s ratio ν₁, whereas the second one by E₂ and ν₂, respectively. Let us consider two modelling cases for functionally graded material (FGM) plates. These cases are related to an appropriate distribution of the material within two-layer and three-layer systems. Our objective is to compare the stiffness of both the two-layer and there-layer plates with the FGM plate containing various proportions between the material components M₁ and M₂.
Źródło:
Journal of Theoretical and Applied Mechanics; 2018, 56, 3; 829-839
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficient numerical modeling of functionally graded shell mechanical behavior
Autorzy:
Koubaa, Sana
Mars, Jamel
Dammak, Fakhreddine
Powiązania:
https://bibliotekanauki.pl/articles/117748.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Promocji Wiedzy
Tematy:
FGM
UMAT-USDFLD
static
free vibration
statyka
wolne wibracje
Opis:
Numerical analysis of the static bending and free vibration mechanical behavior of FGM are performed using the UMAT-USDFLD subroutines in ABAQUS software. Different combinations of geometries, mechanical loading and boundary conditions are adopted. The material properties according to the coordinates of the integration points are defined in the developed numerical model. The First Order Deformation Theory is used for thin and moderately thick FG shells analysis. The accuracy and the robustness of the numerical model are illustrated through the solution of several non trivial structure problems. The proposed numerical procedure is significantly efficient from the computational point of view.
Źródło:
Applied Computer Science; 2019, 15, 1; 84-94
1895-3735
Pojawia się w:
Applied Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the nonlocal interaction range for stability of nanobeams with nonlinear distribution of material properties
Autorzy:
Jankowski, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/2105997.pdf
Data publikacji:
2022
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
nanobeam
FGM
nonlocal strain gradient theory
buckling
piezoelectric effect
Opis:
The present study analyses the range of nonlocal parameters’ interaction on the buckling behaviour of nanobeam. The intelligent nonhomogeneous nanobeam is modelled as a symmetric functionally graded (FG) core with porosity cause nonlinear distribution of material parameters. The orthotropic face-sheets are made of piezoelectric materials. These kinds of structures are widely used in nanoelectromechanical systems (NEMS). The nanostructure model satisfies the assumptions of Reddy third-order beam theory and higher-order nonlocal elasticity and strain gradient theory. This approach allows to predict appropriate mechanical response of the nanobeam regardless of thin or thick structure, in addition to including nano-sized effects as hardening and softening. The analysis provided in the present study focuses on differences in results for nanobeam stability obtained based on classical and nonlocal theories. The study includes the effect of diverse size-dependent parameters, nanobeams’ length-to-thickness ratio and distributions of porosity and material properties through the core thickness as well as external electro-mechanical loading. The results show a dependence of nonlocal interaction range on geometrical and material parameters of nanobeam. The investigation undertaken in the present study provides an interpretation for this phenomenon, and thus aids in increasing awareness of nanoscale structures’ mechanical behaviour.
Źródło:
Acta Mechanica et Automatica; 2022, 16, 2; 151--161
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zagadnienie zakrzywionej anizotropowej oraz funkcjonalnie gradowanej powłoki poddanej działaniu pola temperatury
Problem of curvilinear anisotropic and functionally gradated coating subjected to temperature field
Autorzy:
Szubartowski, D.
Powiązania:
https://bibliotekanauki.pl/articles/194916.pdf
Data publikacji:
2018
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
materiał funkcjonalnie gradientowy
termosprężystość
FGM
functional gradient material
thermo-elasticity
Opis:
Praca dotyczy problematyki zakrzywionej powłoki wykonanej z anizotropowego materiału o funkcyjnej gradacji. W rachunku wykorzystano koncepcję tensora krzywizny Riemanna-Christoffela wzbogaconą o wpływ pola temperatury przez obecność tensora właściwości termicznych. W ramach wykonanych obliczeń różnica wektora poddanego koneksji afinicznej wzdłuż infinitezymalnego czworokąta wyraża się, zależnie od drogi przejścia, sumą zarówno efektu geometrycznego, reprezentowanego tensorem krzywizny Riemanna-Christoffela, jak również efektu termicznego wyrażonego przez symbol krzywizny termicznej.
This work concerns the problem of a curvilinear shell made of anisotropic material with functional gradation. The calculus is based on the concept of the Riemann-Christoffel curvature tensor enhanced by the influence of temperature field through the presence of a thermal tensor. Calculations comprise estimation of the difference of a vector subjected to the affine connection along the infinitesimal quadrangle expressed, correspondingly to the shifting path, by a sum of both the geometric effect, represented by the Riemann-Christoffel curvature tensor, as well as certain symbol of the thermal curvature.
Źródło:
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika; 2018, z. 90 [298], 2; 237-244
0209-2689
2300-5211
Pojawia się w:
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructural Analysis of Sintered Gradient Materials Based on Distaloy SE Powder
Autorzy:
Zarębski, K.
Nykiel, M.
Powiązania:
https://bibliotekanauki.pl/articles/355387.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
functionally graded materials (FGM)
powder metallurgy (PM)
low-alloy steels
Opis:
The study describes the microstructural analysis of cylindrically-shaped functionally graded products sintered from iron powder with scheduled graded structure on the cross-section running from the core to the surface layer of the sinter. Different types of structure were produced using Distaloy SE powder in two compositions - one without the addition of carbon, and another with 0.6wt% C. Two methods were used to fill the die cavity and shape the products. The first method involving a two-step compaction of individual layers. The second method using an original technique of die filling enabled the formation of transition zone between the outer layer and the core still at the stage of product shaping. As part of microstructural analysis, structural constituents were identified and voids morphology was examined. Studies covered the effect of the type of the applied method on properties of the graded zone obtained in the manufactured products.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 2A; 613-620
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Manufacturing of ZrO2-Ni graded composites via centrifugal casting in the magnetic field
Autorzy:
Wachowski, M.
Kosturek, R.
Winkler, H.
Miazga, A.
Lada, P.
Kaszuwara, W.
Konopka, K.
Zygmuntowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/200807.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ZrO2-Ni
ceramic matrix composites
FGM
microstructure
magnetic field
Opis:
The paper presents the possibility of fabricating ceramic-metal composites by an innovative method of centrifugal slip casting in the magnetic field. It was examined whether the use of this method would allow obtaining a gradient concentration of metal particles in the ceramic matrix. In the applied technique, the horizontal rotation axis was used. The study investigated the effect of solid phase content on the properties and microstructure of the products. Water-based suspensions with 35, 40, 45 and 50 vol.% of solid-phase content were prepared with 10 vol.% additional of nickel powder. The viscosity of prepared slurries was considered. The gradient distribution of nickel particles in the zirconia matrix was observed on SEM. Vickers hardness of ZrO2-Ni composites has been measured. The research revealed that the physical properties depend on the volume fraction of solid content and increase as the volume of solid content increases.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 3; 539-545
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Violations of children’s rights in Sudan and their circumstances: the current situation and the possibility of solutions
Autorzy:
KARAMALLA-GAIBALLA, NAGMELDIN
Powiązania:
https://bibliotekanauki.pl/articles/1202990.pdf
Data publikacji:
2021-05-15
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
Sudan
Darfur
children's rights
child labour
FGM/C
underage marriage
Opis:
This paper aims to demonstrate the main aspects and weaknesses of children's rights in Sudan and describe how to work towards enhancing the immediate response to violations against children. This discussion will help develop future plans to strengthen the enforcement of children’s rights in Sudan and create an environment that protects children's rights against all kinds of violations. This paper presents the current situation of children’s rights violations in Sudan and factors that have a great and direct impact on these situations, especially social and cultural factors concerning female circumcision, genital mutilation, and marriage of underage girls; and laws that violate the dignity of Sudanese children, such as laws related to flogging, imprisonment, and death. The article also addresses issues of wars and internal conflicts and their impact on children, including their recruitment and trafficking. It also discusses the weaknesses of laws in place to protect children in Sudan and the changes these laws have undergone in recent years, especially the fundamental changes following the revolution that broke out in Sudan in 2018, which replaced the dictatorial military regime with Islamic orientations and trying to find objective solutions.
Źródło:
Society Register; 2021, 5, 2; 57-68
2544-5502
Pojawia się w:
Society Register
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non-stationary heat transfer in two-phase hollow cylinder with functionally graded effective material properties with second kind of boundary conditions
Niestacjonarny przepływ ciepła w przewodniku cylindrycznym z warunkami brzegowymi drugiego rodzaju
Autorzy:
Ostrowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/395935.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
przewodnictwo cieplne
niestacjonarny przepływ ciepła
kompozyt
heat conduction
FGM
composite
Opis:
The unidirectional non-stationary heat conduction in two-phase hollow cylinder is considered. The conductor is made of two-phase stratified composites and has a smooth gradation of effective properties in the radial direction. Therefore, we deal here with a special case of functionally graded materials, FGM (cf. [6]). The formulation of mathematical model of the conductor is based on the tolerance averaging approach (TAA), cf. [8]. Considerations in this paper are restricted only to the unidirectional nonstationary heat conduction, where on the boundaries are given [phi]-constant or periodic function of heat fluxes q_o = q_o([phi]t), qk = qk([phi]t) for every time period t, and function of initial temperature [...]. The effect of fibres width on the temperature field will be also examined.
Przedmiotem rozważań niniejszej pracy jest analiza wpływu pewnych parametrów geometrycznych przewodnika na przebieg pola temperatur dla zagadnienia niestacjonarnego przepływu ciepła. Rozpatrywany przewodnik jest dwuskładnikowym kompozytem o deterministycznej mikrostrukturze, który w kierunku kątowym jest .- periodyczny (dla ustalonego promienia .), a w kierunku promieniowym jego efektywne własności zmieniają się w sposób wolnozmienny. Stąd, mamy tutaj do czynienia ze szczególnym przypadkiem materiału o funkcyjnej gradacji własności, FGM (por. Suresh , Mortensen, 1998). Samo zjawisko przewodznia ciepła opisane jest równaniem Fouriera, które zawiera nieciągłe i silnie oscylujące współczynniki. Model matematyczny opisujący zjawisko przewodzenia ciepła w rozpatrywanym kompozycie opierać się będzie na technice tolerancyjnej aproksymacji (por. Woźniak, Wierzbicki, 2000). W pracy ograniczymy się jedynie do przypadku jednowymiarowego przepływu ciepła, w którym na brzegach przewodnika dana jest stała bądź periodyczna funkcja gęstości strumienia ciepła q0 = q0(.,t), qk = qk(.,t) dla dowolnej chwili czasu t, oraz funkcja pola temperatury .0 = .0(.,t) w chwili początkowej t = t0. Rozpatrywano również wpływ szerokości inkluzji na prędkość zmian pola temperatury w obszarze przewodnika.
Źródło:
Civil and Environmental Engineering Reports; 2010, 5; 113-122
2080-5187
2450-8594
Pojawia się w:
Civil and Environmental Engineering Reports
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The analysis of non-linear free vibration of FGM nano-beams based on the conformable fractional non-local model
Autorzy:
Rahimi, Z.
Sumelka, W.
Shafiei, S.
Powiązania:
https://bibliotekanauki.pl/articles/201202.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
FGM nano beam
nonlinear free vibration
fractional calculus
integer stress
non-integer stress
gradient’s order
fractional non-local model
rachunek różniczkowy
FGM
drgania swobodne
Opis:
Continuum models generalized by fractional calculus are used in different mechanical problems. In this paper, by using the conformable fractional derivative (CFD) definition, a general form of Eringen non-local theory as a fractional non-local model (FNM) is formulated. It is then used to study the non-linear free vibration of a functional graded material (FGM) nano-beam in the presence of von-Kármán non-linearity. A numerical solution is obtained via Galerkin and multiple scale methods and effects of the integer and non-integer (fractional) order of stress gradient (in the non-local stress-strain relation) on the ratio of the non-local non-linear natural frequency to classical non-linear natural frequency of simply-supported (S-S) and clamped-free (C-F) FGM nano-beams are presented.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2018, 66, 5; 737-745
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some aspects of dynamic coupled response of functionally graded thin-walled columns with square cross-sections under in-plane pulse compression
Autorzy:
Kołakowski, Z.
Teter, A.
Powiązania:
https://bibliotekanauki.pl/articles/279439.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
FGM
dynamic response
interactive buckling
thin-walled structures
compression
pulse load
Opis:
The present paper deals with a dynamic coupled response of functionally graded columns with a quadratic cross-section subjected to an in-plane pulse loading. An Al-TiC metal- -ceramic material is applied. It is assumed that functionally graded materials (FGMs) are subject to Hooke’s law. The thin-walled structures are simply supported at the ends. This study is devoted to the stability problem of rectangular dynamic pulse load. The effects of temperature, wave propagation and damping are neglected. In order to obtain the equations of motion of individual plates, the classic laminate plate theory (CLPT) has been modified in such a way that it additionally accounts for all components of inertial forces. A plate model is adopted for the structures. The problem of an interaction of the global mode with the local ones is concerned (i.e., a three-modes approach). Attention has been focused on some unexpected aspects related to dynamic interactive buckling of columns having two axes of the cross-section symmetry. In the present study, a new approach to the description of this phenomenon, based on Koiter’s theory, has been applied.
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 2; 449-462
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical study of the mechanical behaviour and damage of fgm bent pipes under internal pressure and combined bending moment
Autorzy:
Houari, Amin
Madani, Kouider
Amroune, Salah
Zouambi, Leila
Elajrami, Mohamed
Powiązania:
https://bibliotekanauki.pl/articles/2233650.pdf
Data publikacji:
2023
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
FGM
ceramic metals
elbow pipe
internal pressure
bending moment
MMU technique
Opis:
The main objective of this work is the numerical prediction of the mechanical behaviour up to the damage of the bends of the functionally graded material (FGM) type ceramic/metal pipes. Firstly, the effective elastoplastic proper-ties of bent FGM pipes were determined using the homogenisation law by the Mori–Tanaka models for the elastic part and TTO (Tamura-Tomota-Ozawa) for the plastic part based on a rule of mixtures per function in the form of a power law. Our work also aims at the use of a meshing method (UMM) to predict the behaviour of the FGM by finite element in the mesh of the model. The analysis was performed using the UMM technique for different loading cases and volume fraction distribution. Two stages are necessary for the analysis of the damage: the first is the model of initiation of the damage established by the criterion of maximum deformation named MAXPE and the second is criterion of the energy of the rupture according to the theory Hillerborg used to determine damage evolution. Both stages involve a 3D finite element method analysis. However, for damage, the XFEM technique was used in our UMM method to predict crack initiation and propagation in FGM pipe bends. The results of the numerical analysis concerning the mechanical behavior showed, that if the nature of the bent pipes is in FGM, a good reduction of the various stresses compared to those where the nature of the pipe is metallic material. The results were presented in the form of a force–displacement curve. The validation of the proposed numerical methodology is highlighted by comparisons of current results with results from the literature, which showed good agreement. The analysis took into account the effect of the main parameters in a bent FGM pipe under internal pressure and bending moment on the variation of the force–strain curves.
Źródło:
Acta Mechanica et Automatica; 2023, 17, 3; 460--468
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of material gradient on the static and dynamic response of layered functionally graded material plate using finite element method
Autorzy:
Vasiraja, N.
Nagaraj, P.
Powiązania:
https://bibliotekanauki.pl/articles/201107.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
FGM plate
finite element
power law index
buckling load
fundamental frequency
ANSYS®
Opis:
This article focuses on the finite element analysis (FEA) of the nonlinear behavior of a layered functionally graded material (FGM) plate as concerns displacement, stresses, critical buckling load and fundamental frequency. The material properties of each layer in an FGM plate are assessed according to a ceramic based simple power law distribution and the rules of mixture. The finite element model of a layered FGM plate is developed using ANSYS®15.0 software. The developed finite element model is used to study the static and dynamic responses of an FGM plate. In this paper, the effects of power law distribution, thickness ratio, aspect ratio and boundary conditions are investigated for central displacement, transverse shear stress, transverse normal stress, critical buckling load and fundamental frequency, and the obtained FEA results are in sound agreement with the literature test data results. Since the FGM is used in a high temperature environment, the FE analysis is performed for the FGM plate under a thermal field and then correlated. Finally, the FGM plate is analyzed under a thermomechanical load by using the current FE concept.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2019, 67, 4; 827-838
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influences of porosity and tangential edge constraint on thermo-torsional postbuckling of FGM toroidal shell segments surrounded by an elastic medium
Autorzy:
Nhu Trang, L. T.
Van Tung, H.
Powiązania:
https://bibliotekanauki.pl/articles/38697106.pdf
Data publikacji:
2023
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
nonlinear buckling
porous FGM
toroidal shell segment
tangential edge constraint
torsional load
Opis:
For the first time, simultaneous influences of porosities, tangential constraints of boundary edges, surrounding elastic media and elevated temperature on the buckling and postbuckling behaviors of a functionally graded toroidal shell segment are investigated in this paper. Porosities exist in the functionally graded material (FGM) according to even and uneven distributions. Properties of constituent materials are assumed to be temperature dependent and effective properties of the porous FGM are determined using a modified rule of mixture. Governing equations are based on the classical shell theory taking into account geometrical nonlinearity and interactive pressure from surrounding elastic medium. Multi-term analytical solutions are assumed to satisfy simply supported boundary conditions and the Galerkin method is adopted to derive nonlinear load – deflection relations and buckling loads. Parametric studies are carried out to analyze the effects of porosity, shell geometry, degree of tangential edge constraint, elevated temperature and elastic media on the buckling resistance and postbuckling strength of toroidal shell segments under a torsional load. The study reveals that tangential edge restraints have considerably beneficial and detrimental influences on the nonlinear stability of torsion-loaded FGM shells at room and elevated temperatures, respectively. The results also find out that the shear layer and the elastic layer of surrounding medium significantly enhances and alleviates the buckling resistance capacity and severity of the snap-through response of the torsion-loaded porous FGM toroidal shell segment, respectively.
Źródło:
Archives of Mechanics; 2023, 75, 4; 401-429
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Elastic solution of pressurized clamped-clamped thick cylindrical shells made of functionally graded materials
Autorzy:
Ghannad, M.
Nejad, M. Z.
Powiązania:
https://bibliotekanauki.pl/articles/949147.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
clamped-clamped thick cylinder
functionally graded material (FGM)
shear deformation theory (SDT)
Opis:
The effect of material inhomogeneity on displacements and stresses of an internally pressurized clamped-clamped thick hollow cylinder made of functionally graded materials is investigated. The modulus of elasticity is graded along the radial direction according to power functions of the radial direction. It is assumed that Poisson’s ratio is constant across the cylinder thickness. The governing differential equations were generally derived, making use of the first-order shear deformation theory (FSDT). Following that, the set of non-homogenous linear differential equations for the cylinder with clamped-clamped ends was solved, and the effect of loading and supports on the stresses and displacements was investigated. The problem was also solved, using the finite element method (FEM), the results of which were compared with those of the analytical method.
Źródło:
Journal of Theoretical and Applied Mechanics; 2013, 51, 4; 1067-1079
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transient analysis of transversely functionally graded Timoshenko beam (TFGTB) in conjunction with finite element method
Autorzy:
Khafaji, Salwan Obaid Waheed
Al-Shujairi, Mohammed A.
Aubad, Mohammed Jawad
Powiązania:
https://bibliotekanauki.pl/articles/140231.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
FGM beam
transient response
free vibration
fundamental frequency
finite element method
Timoshenko beam theory
Opis:
In this work, transient and free vibration analyses are illustrated for a functionally graded Timoshenko beam (FGM) using finite element method. The governing equilibrium equations and boundary conditions (B-Cs) are derived according to the principle of Hamilton. The materials constituents of the FG beam that vary smoothly along the thickness of the beam (along beam thickness) are evaluated using the rule of mixture method. Power law index, slenderness ratio, modulus of elasticity ratio, and boundary conditions effect of the cantilever and simply supported beams on the dynamic response of the beam are studied. Moreover, the influence of mass distribution and continuous stiffness of the FGM beam are deeply investigated. Comparisons between the current free vibration results (fundamental frequency) and other available studies are performed to check the formulation of the current mathematical model. Good results have been obtained. A significant effect is noticed in the transient response of both simply supported and cantilever beams at the smaller values of the power index and the modulus elasticity ratio.
Źródło:
Archive of Mechanical Engineering; 2020, LXVII, 3; 299-321
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exact and Numerical Elastic Analysis for the FGM Thick-Walled Cylindrical Pressure Vessels with Exponentially-Varying Properties
Autorzy:
Nejad, M. Z.
Abedi, M.
Lotfian, M. H.
Ghannad, M.
Powiązania:
https://bibliotekanauki.pl/articles/355232.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cylindrical pressure vessel
thick-walled
Functionally Graded Material (FGM)
Finite element method (FEM)
exponential
Opis:
Assuming exponential-varying properties in the radial direction and based on the elasticity theory, an exact closed-form analytical solution is obtained to elastic analysis of FGM thick-walled cylindrical pressure vessels in the plane strain condition. Following this, radial distribution of radial displacement, radial stress, and circumferential stress are plotted for different values of material inhomogeneity constant. The displacements and stresses distributions are compared with the solutions of the finite element method (FEM).
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 3; 1649-1654
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulation of thermal shock of FGMS disks
Symulacja numeryczna szoku termicznego dysków gradientowych
Autorzy:
Niezgoda, T.
Boniecki, M.
Kosiuczenko, K.
Barnat, W.
Powiązania:
https://bibliotekanauki.pl/articles/246450.pdf
Data publikacji:
2007
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
MES (metoda elementów skończonych)
materiały gradientowe
szok termiczny
naprężenia
FEM
FGM
stress
thermal shock
Opis:
Praca zawiera opis symulacji numerycznej szoku termicznego w cylindrycznych próbkach kompozytowych o zróżnicowanej grubości. Próbki wykonano z materiałów gradientowych na bazie aluminy Al2O3, z warstwami o zróżnicowanej zawartości cyrkonii zro2 w każdej warstwie. W celu przeprowadzenia oceny otrzymanych wyników numerycznych wykonano eksperyment. Wykorzystywane w obliczeniach parametry materiałowe obliczono w oparciu o wzory zaczerpnięte z teorii mieszanin. Symulację przeprowadzono wykorzystując metodę elementów skończonych zaimplementowaną w programie LS-Dyna. Modele numeryczne symulacji składały się z siatki elementów bryłowych 6 i 8-węzłowych z 3 stopniami swobody w każdym węźle, opisującej 5-stopniowy wycinek krążka. Odpowiedni sposób zdefiniowania warunków brzegowych umożliwił zmniejszenie wielkości zadania numerycznego poprzez wykorzystanie osiowej symetrii Otrzymane wyniki symulacji numerycznej pozwalają ocenić poziom naprężeń w materiale gradientowym poddanym szokowi termicznemu. Pozwalają na świadome kształtowanie odporności termicznej barier cieplnych, nie tylko modyfikując ich grubość, ale również skład chemiczny warstw. Zestawienie wyników symulacji numerycznej i eksperymentu pokazuje niewielkie różnice w przebiegach wykresów temperatur, co świadczy o poprawności zamodelowania zjawiska.
The paper presents a description of the numerical simulation of the thermal shock in cylindrical composite specimens of diversified thickness. The specimens were made of graded materials (Al2O3 with various admixture of ZrO2). The material parameters used in numerical calculations were calculated on the grounds of the mixture method. The simulation was carried out using the Finite Element Method implemented in the LS-Dyna code. The results of numerical calculations were verified experimentally. The aim of the paper is theoretical modelling of the thermal shock problem in a strip made of functionally graded composite (FGMs). The distributions of thermal are analyzed respectively by thermo-mechanical finite element analysis (FEA). The propagation of stress in fgms is studied numerically by means of the LS Dyna code. The numerical simulation demonstrates the applicability of the algorithm to the modeling of FGM without any averaging procedure. The thermal shock resistance of disks (780 centigrade) was evaluated by sudden cooling with a high-velocity nitrogen jet at room temperature (20 centigrade).
Źródło:
Journal of KONES; 2007, 14, 3; 459-465
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 36

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