Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "couple stress theory" wg kryterium: Temat


Wyświetlanie 1-7 z 7
Tytuł:
Dispersion of Rayleigh Waves in a Microstructural Couple Stress Substrate Loaded with Liquid Layer Under the Effects of Gravity
Autorzy:
Sharma, V.
Kumar, S.
Powiązania:
https://bibliotekanauki.pl/articles/947783.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
couple stress theory
Rayleigh waves
gravity
characteristic length
liquid loading
Opis:
Bone loss is one of the serious health issues in bedridden patients or young generation due to lack of physical activities. Mechanical forces are exerted on the bones through ground reaction forces, liquid loadings and by other contraction activities of the muscles. We are assuming an isotropic half-space with mechanical properties equivalent to that of bone exhibiting microstructures. Consistent couple stress theory introduces an additional material parameter called characteristic length which accounts for inner microstructure of the material. Dispersion relations for leaky Rayleigh waves are derived by considering a model consisting of couple stress half space under the effects of gravity and loaded with inviscid liquid layer of finite thickness or a liquid half space. Impact of the gravity, liquid loadings and microstructures of the material are investigated on propagation of leaky Rayleigh type waves. Phase velocity of leaky Rayleigh waves is studied for five different values of characteristic length parameter which are of the order of internal cell size of the considered material. Variations in phase velocity of leaky Rayleigh waves are also studied under the effect of gravity parameter and thickness of liquid loadings.
Źródło:
Archives of Acoustics; 2018, 43, 1; 11-20
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dispersion of SH waves in a viscoelastic layer imperfectly bonded with a couple stress substrate
Autorzy:
Sharma, V.
Kumar, S.
Powiązania:
https://bibliotekanauki.pl/articles/949130.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
SH waves
couple stress theory
imperfect bonding
characteristic length
viscoelasticity
Opis:
The paper deals with propagation of SH waves in a viscoelastic layer over a couple stress substrate with imperfect bonding at the interface. A dispersion equation of SH waves in a viscoelastic layer overlying the couple stress substrate with an imperfect interface between them has been obtained. Dispersion equations for propagation of SH waves with perfectly bonded interface and slippage interface between two media are also obtained as particular cases. Effects of the degree of imperfectness of the interface are studied on the phase velocity of SH waves. The dispersion curves are plotted and the effects of material properties of both couple stress substrate and viscoelastic layer are studied. The effects of internal microstructures of the couple stress substrate in terms of characteristic length of the material are presented. The effects of heterogeneity, friction parameter and thickness of the viscoelastic layer are also studied on the propagation of SH waves.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 2; 535-546
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A multi-spring model for buckling analysis of cracked Timoshenko nanobeams based on modified couple stress theory
Autorzy:
Akbarzadeh Khorshidi, M.
Shariati, M.
Powiązania:
https://bibliotekanauki.pl/articles/281289.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
buckling
crack
modified couple stress theory
Timoshenko nanobeam
spring model
Opis:
This paper develops a cracked nanobeam model and presents buckling analysis of this developed model based on a modified couple stress theory. The Timoshenko beam theory and simply supported boundary conditions are considered. This nonclassical model contains a material length scale parameter and can interpret the size effect. The cracked nanobeam is modeled as two segments connected by two equivalent springs (longitudinal and rotational). This model promotes discontinuity in rotation of the beam and additionally considers discontinuity in longitudinal displacement due to presence of the crack. Therefore, this multi-spring model can consider coupled effects between the axial force and bending moment at the cracked section. The generalized differential quadrature (GDQ) method is employed to discretize the governing differential equations, boundary and continuity conditions. The influences of crack location, crack severity, material length scale parameter and flexibility constants of the presented spring model on the critical buckling load are studied.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 4; 1127-1139
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Free vibration of a hyper-elastic microbeam using a new “augmented Biderman model”
Autorzy:
Karami Mohammadi, Ardeshir
Danaee Barforooshi, Saeed
Powiązania:
https://bibliotekanauki.pl/articles/949138.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
nonlinear vibration
hyper-elastic microbeam
augmented Biderman model
modified couple stress theory
Opis:
A new augmented Biderman model inspired by the modified couple stress theory has been introduced to investigate the size effect in addition to nonlinear material effects. Then, this model is used to investigate free vibration of a hyper-elastic microbeam. Classical Biderman strain energy does not include the effect of small size in hyper-elastic materials. In order to consider the effect of small size, terms inspired by the modified couple stress theory are added to the classical Biderman strain energy function. In order to provide the possibility of calculating these terms, a relation between the material constants in the hyper-elastic Biderman model and the linear elastic constants is obtained. The equations of motion of the microbeam is obtained based on the extended Hamilton principle, and then is solved using Galerkin discretization and perturbation methods. The effect of thickness to length scale ratio on the normalized frequency is studied for different modes. It is shown that when thickness gets larger in comparison with the length scale parameter, the normalized frequency tends to classical Biderman results. The results obtained are validated by results of the Runge-Kutta numerical method and indicate an excellent agreement. Mode shapes of the microbeam based on the classical and the augmented models are depicted, where the augmented model anticipates stiffer behavior for hyperelastic microbeams.
Źródło:
Journal of Theoretical and Applied Mechanics; 2019, 57, 3; 739-750
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transient dynamic analysis of functionally graded micro-beams considering small-scale effects
Autorzy:
Eshraghi, I.
Dag, S.
Powiązania:
https://bibliotekanauki.pl/articles/38627524.pdf
Data publikacji:
2021
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
boundary element method
functionally graded materials
Timoshenko micro-beam
vibrations
modified couple stress theory
Opis:
A domain-boundary element method, based on modified couple stress theory, is developed for transient dynamic analysis of functionally graded micro-beams. Incorporating static fundamental solutions as weight functions in weighted residual expressions, governing partial differential equations of motion are converted to a set of coupled integral equations. A system of ordinary differential equations in time is obtained by domain discretization and solved using the Houbolt time marching scheme. Developed procedures are verified through comparisons to the results available in the literature for micro- and macro-scale beams. Numerical results illustrate elastodynamic responses of graded micro-beams subjected to various loading types. It is shown that metal-rich micro-beams and those with a smaller length scale parameter ratio undergo higher displacements and are subjected to larger normal stresses.
Źródło:
Archives of Mechanics; 2021, 73, 4; 303-337
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Free vibration analysis of porous functionally graded piezoelectric microplates resting on an elastic medium subjected to electric voltages
Autorzy:
Wu, C.-P.
Lin, E.-L.
Powiązania:
https://bibliotekanauki.pl/articles/38695702.pdf
Data publikacji:
2022
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
consistent couple stress theory
functionally graded material
Winkler-Pasternak foundation
piezoelectric microplates
porous microplates
vibration
Opis:
Basing on the consistent couple stress theory (CCST), we develop a unified size-dependent shear deformation theory to analyze the free vibration characteristics of simply supported, porous functionally graded (FG) piezoelectric microplates which resting on the Winkler-Pasternak foundation are subjected to electric voltages. Various CCST-based shear deformation theories can be reproduced by incorporating their corresponding shape functions, which characterize the through-thickness distributions of the shear deformations, into the unified size-dependent theory. The reproduced CCST-based plate theories include the classical plate theory (CPT), the first-order shear deformation plate theory (SDPT), Reddy’s refined SDPT, the sinusoidal SDPT, the exponential SDPT, and the hyperbolic SDPT. The unified size-dependent theory is subsequently used to determine the natural frequencies of simply supported, porous FG piezoelectric microplates and their corresponding vibration mode shapes. The effects of the material length scale parameter, the length-to-thickness ratio, the material-property gradient index, different values of the applied voltages, the porosity parameter, different porosity distribution patterns, the Winkler spring coefficient, and the shear modulus of the surrounding medium on the natural frequencies of the porous FG piezoelectric microplates are examined and appear to be significant.
Źródło:
Archives of Mechanics; 2022, 74, 6; 463-511
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nonlinear Free Vibration Analysis of Micro-beams Resting on Viscoelastic Foundation Based on the Modified Couple Stress Theory
Autorzy:
Jam, J. E.
Noorabadi, M.
Namdaran, N.
Powiązania:
https://bibliotekanauki.pl/articles/139530.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nonlinear free vibration
size dependence
modified couple stress theory
Euler-Bernoulli beam model
Galerkin method
swobodne drgania nieliniowe
zależność od wielkości
zmodyfikowana teoria naprężeń momentowych
model belki Eulera-Bernouliego
metoda Galerkina
Opis:
In this paper, nonlinear free vibration analysis of micro-beams resting on the viscoelastic foundation is investigated by the use of the modified couple stress theory, which is able to capture the size effects for structures in micron and sub-micron scales. To this aim, the governing equation of motion and the boundary conditions are derived using the Euler–Bernoulli beam and the Hamilton’s principle. The Galerkin method is employed to solve the governing nonlinear differential equation and obtain the frequency-amplitude algebraic equation. Finally, the effects of different parameters, such as the mode number, aspect ratio of length to height, the normalized length scale parameter and foundation parameters on the natural frequency-amplitude curves of doubly simply supported beams are studied.
Źródło:
Archive of Mechanical Engineering; 2017, LXIV, 2; 239-256
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-7 z 7

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies