PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 12

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  drganie swobodne
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available remote Forced and free vibrational analysis of viscoelastic nanotubes conveying fluid subjected to moving load in hygro-thermo-magnetic environments with surface effects
Sarparast Hoda, Alibeigloo Akbar, Borjalilou Vahid, Koochakianfard Omid
Archives of Civil and Mechanical Engineering
|
2022
|
Vol. 22, no. 4
art. no. e172, 2022
EN
Forced and free vibrational analyses of viscoelastic nanotubes containing fluid under a moving load in complex environments incorporating surface effects are conducted based on the nonlocal strain gradient theory and the Rayleigh beam model. To model the internal nanoflow, the slip boundary condition is employed. Adopting the Galerkin discretization approach, the reduced-order dynamic model of the system is acquired. Analytical and numerical methods are exploited to determine the dynamic response of the system. The impacts of geometry, scale parameter ratio, Knudsen number, fluid velocity, rotary inertia parameter, viscoelastic parameter, surface residual stress, surface elastic modulus, and hygro-thermo-magnetic environments on the dynamic magnification factor, critical moving load speed, cancellation, and maximum free vibration of the system are evaluated. The results indicate that the effects of the viscoelastic parameter on the dynamic behavior of the system differ significantly from those of other parameters. It is indicated that the dynamic magnification factor and critical moving load speed are enhanced by increasing the surface residual stress and the surface elastic modulus. The model and results of the current investigation can serve as a comprehensive benchmark for the optimum design of nanoflow sensors and targeted drug delivery systems.
2
Content available Application of Laplace Transform to the free vibration of continuous beams
Wen H. B., Zeng T., Hu G. Z.
Archives of Civil Engineering
|
2017
|
Vol. 63, nr 1
163--180
EN
Laplace Transform is often used in solving the free vibration problems of structural beams. In existing research, there are two types of simplified models of continuous beam placement. The first is to regard the continuous beam as a single-span beam, the middle bearing of which is replaced by the bearing reaction force; the second is to divide the continuous beam into several simply supported beams, with the bending moment of the continuous beam at the middle bearing considered as the external force. Research shows that the second simplified model is incorrect, and the frequency equation derived from the first simplified model contains multiple expressions which might not be equivalent to each other. This paper specifies the application method of Laplace Transform in solving the free vibration problems of continuous beams, having great significance in the proper use of the transform method.
PL
Struktury ciągłej wiązki są bardzo często spotykane w projektach budowlanych. Przykłady obejmują: mostki ciągłej wiązki, stopy budynków, rury do wymiany ciepła w wymiennikach ciepła oraz wrzeciona obrabiarki. Nieodłączną częścią projektowania struktur ciągłych wiązek jest dynamiczna charakterystyczna analiza konstrukcji jako podstawy projektu antywibracyjnego. W celu uzyskania dynamicznych charakterystycznych parametrów struktur ciągłych wiązek, uczeni z kraju i z zagranicy przyjęli w celu poszukiwania rozwiązań liczne metody, w tym metodę elementów skończonych, metodę sztywności dynamicznej oraz metodę transferu matrycy. Metoda analityczna, w której wykorzystywane jest przekształcenie Laplace’a, mająca na celu rozwiązanie problemu wolnych drgań ciągłych wiązek, jest preferowana przez wielu badaczy i szeroko stosowana do rozwiązywania takich problemów w wielu dziedzinach. Niemniej jednak, istnieją pewne błędy w stosowaniu przekształcenia Laplace’a. W związku z tym, w niniejszej pracy przeprowadzono badania i analizę dotyczące różnych metod stosowania przekształcenia Laplace’a. Ponadto, w niniejszym dokumencie wyjaśniono metodę prawidłowego zastosowania przekształcenia Laplace’a podczas rozwiązywania problemu wolnego drgania ciągłej wiązki.
3
Content available remote Model poprzecznych swobodnych drgań piły taśmowej i jej prędkość krytyczna
Kaliński W., Wojnarowski J.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2005
|
z. 65 [222]
167-174
EN
Periodic band tension variations may induce the large amplitude of transverse band saw vibrations. The purpose of this paper is to present a theoretical analysis of band saw vibrations. Some results of the analysis for modern band and band mill are discussed.
4
Content available remote Free longitudinal vibrations of an elastically connected double – rod system
Oniszczuk Z.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2005
|
z. 65 [222]
303-310
EN
In this work, the theoretical longitudinal vibration analysis of an elastically connected double-rod system is presented. The double-rod system is the model of a complex continuous system, which is composed of two straight, uniform elastic rods attached together by a Winkler elastic layer. The motion of the system is described by a coupled set of two non-homogeneous partial differential equations, which can be solved by using the classical mathematical methods. Solutions of undamped free vibrations are formulated by applying the modal expansion method. Two infinite sequences of the natural frequencies and corresponding mode shape functions expressing synchronous and asynchronous vibrations of the system are determined. The initial-value problem is considered to find the final form of free vibrations.
5
Content available remote Badania wpływu układu rama nadwozia wysięgnik teleskopowy na drgania swobodne ramy podwozia żurawia samochodowego
Geisler T.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
2005
|
z. 65 [222]
117-124
EN
The free vibration problem of the truck crane chassis frame with attached rotating frame and telescopic boom is considered. The formulation and solution of the problem have been done by the use of finite element method and the system COSMOS/M. On the basis of the formulated model the investigations of the influence of the rotating frame position on the system's free vibration frequencies and mode shapes have been done.
6
Magnetoelastic forced and free vibrations of ferromagnetic plates in direct transverse or longitudinal electromagnetic fields
Vantsyan A. A.
Journal of Technical Physics
|
2004
|
Vol. 45, no 3
237-241
EN
The experimental investigations of the problem of bending vibrations of magnetoelastic and ferromagnetic plates are carried out. The amplitudes of displacements, velocities and accelerations are evaluated and the corresponding curves as functions of the magnetic field, longitudinal or transverse, are drawn. It is shown that they have extremal character. Also graphs of frequencies of free vibrations of plates as functions of magnetic field are given, what is in agreement with the spatial theory developed by ourselves.
7
Modelowanie drgań swobodnych połączonych sprężyście układów prętowych
Posiadała B.
Zeszyty Naukowe. Mechanika / Politechnika Opolska
|
2001
|
z. 69
439-446
8
Content available remote Modelowanie swobodnych drgań poprzecznych wysięgników teleskopowych
Posiadała B.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
z. 52 [174]
195-200
EN
The problem of free transverse vibrations of telescopic booms is considered. The model of the boom consists of Bernoulli-Euler beams connected by translational spring system. The frequency equation for the combined system is derived by means of the Lagrange multiplier formalism. The validity of the present method is confirmed by the results of numerical computations.
9
Content available remote Free vibration analysis of elastically connected double-string complex system
Oniszczuk Z.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
z. 52 [174]
327-332
PL
W pracy analizuje się swobodne, nietłumione drgania poprzeczne złożonego układu dwóch cięgien połączonych winklerowskim elementem sprężystym. Rozwiązanie problemu formułuje się wykorzystując metodę Bemoulliego - Fouriera. Rozpatruje się zagadnienie brzegowo-początkowe wyznaczając częstości i postacie drgań własnych. Ruch drgający układu realizuje się w formie drgań synchronicznych i asynchronicznych.
10
Content available remote Drgania swobodne układu belek modelującego wysięgnik teleskopowy
Kukla S.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
z. 52 [174]
171-176
EN
This paper deals with the problem of free vibration of a system of elastically connected Timoshenko beams. The system of beams is a model of the three-member telescopic boom. The investigation concerns the transverse vibration of the boom. The solution of the problem has been obtained by applying a Green function method. The numerical results has been compared with those obtained by using the finite element method.
11
Content available remote Analiza wrażliwości częstości skrętnych drgań swobodnych belki dwuteowej z przeponami
Szymczak C., Iwicki P., Mikulski T.
Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika
|
1999
|
z. 52 [174]
351-356
EN
The sensitivity analysis of torsional vibration frequencies of thin-walled I-beams with stiffeners is discussed. First order variation of simple eigenvalues due to the design variable variations is derived. The stiffener dimensions and its material constants are assumed to be the design variables. The considerations are based on the theory of thin-walled beams with nondeformable cross-section. The underintegral sensitivity functions of the variations of the square free vibration frequencies due to the variation of stiffener thickness' for a simply supported I-beam are determined. An approximation accuracy of the natural frequencies changes resulting from the design variable change by means of their first-order sensitivity analysis are also investigated.
12
Content available remote Free vibration of the system of two strings coupled by a viscoelastic interlayer
Cabańska-Płaczkiewicz K.
Engineering Transactions
|
1998
|
Vol. 46, iss. 2
217-227
EN
This paper introduces an analytical method of solving the free vibration problem for a continuous system of two strings coupled by a viscoelastic interlayer. The phenomenon of free vibration has been described using a homogenous system of conjugate partial differential equations. After separation of variables in the system of differential equations, the boundary problem has been solved and two complex sequences have been obtained : the sequence of frequency, and the sequence of modes of free vibration. Then, the property of orthogonality of complex modes of free vibration has been demonstrated. Based on complex eigenfunctions, the polyharmonic free vibration has been expanded into the complex Fourier series, coefficients of which have been determined for arbitrarily assumed initial conditions.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.