Wyniki wyszukiwania - BazTech

1

Application of translational edge restraint for vibration analysis of free edge Kirchhoff’s plate including rigid-body modes

Verma Y., Datta N.

Engineering Transactions

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2018

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Vol. 66, iss. 1

21--60

EN

A comprehensive theoretical study of closed-form rigid-body modes of a free-free and translationally edge-restrained Euler-Bernoulli beam is presented. Accurate vibrational analysis of a free-free-free-free plate is not possible without the inclusion of degenerate rigid-body beamwise admissible functions. The trivial solution(s) of the beam frequency equation produce(s) a non-trivial modeshape, which satisfies the boundary conditions, has zero curvature, and is orthogonal to the other modeshapes. These frequency parameters are “trivial”, i.e. they lead to zero natural frequency, since their modeshapes have no curvature. Mathematicallygenerated orthogonal free-free (classical) beam-wise rigid-body modeshapes, and those generated from non-classical edged beams, have been both separately used as admissible functions in the Rayleigh-Ritz method (RRM) to generate the plate natural frequencies of a free-freefree-free rectangular uniform isotropic Kirchhoff’s plate. With respect to the increasing elastic support, the trifurcation and bifurcation of plate frequencies from the trivial to the flexural frequencies, is investigated. The completely free plate modeshapes are also presented. Also, combination of present closed-form rigid-body modes with polynomial functions, trigonometric functions is also demonstrated.

2

Influence of mixed boundary conditions and heterogeneity on the vibration behavior of orthotropic truncated conical shells

Sofiyev A. H., Huseynov S. E., Kuruoglu N.

Archives of Mechanics

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2015

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Vol. 67, nr 4

331--348

EN

This paper presents the vibration behavior analysis of heterogeneous orthotropic conical shells with mixed boundary conditions. Basic equations of heterogeneous orthotropic truncated conical shells are derived using Donnell–Mushtari shell theory. Employing the separation of variables and Galerkin’s method, the expressions for frequency of heterogeneous orthotropic conical shells with two mixed boundary conditions are obtained. The results are validated through numerical comparisons with available results in the literature. The influences of truncated shell characteristics, heterogeneity, material orthotropy and mixed boundary conditions on dimensionless frequency parameters are investigated.

3

Parametry częstotliwościowe przetworników prądowych wykonanych w technologii PCB1 i HDI2

Lisowiec A., Nowakowski A.

Mechanizacja i Automatyzacja Górnictwa

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2014

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R. 52, nr 5

12--17

PL

W artykule przedstawiono wyniki pomiarów oraz analizę charakterystyk częstotliwościowych przetworników prądowych wykonanych w technologii PCB HDI. Najpierw omówiono konstrukcję bez-rdzeniowych przetworników wykonanych w technologii PCB HDI. Następnie określono wartości elementów układu zastępczego przetwornika bezrdzeniowego. Na koniec przytoczono charakterystyki częstotliwościowe przetworników bezrdzeniowych wykonanych w tradycyjnej technologii PCB oraz w technologii HDI.

EN

The article presents the measurement results and analysis of frequency characteristics of current-mode converters made with the use of the PCB HDI technology. First the structure of rodless PCB HDI converters was discussed. Then the values of the elements of an equivalent circuit in a rodless converter were determined. Finally, the authors discussed the frequency characteristics of rodless converters made with the use of either the traditional PCB technology or the HDI technology.

4

Unsteady Hartmann flow in a rotating channel with perfectly conducting walls

Seth G. S., Ansari Md. S., Nandkeolyar R.

International Journal of Applied Mechanics and Engineering

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2011

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Vol. 16, no 4

1129-1146

EN

An unsteady Hartmann flow of a viscous incompressible electrically conducting fluid in a rotating channel with perfectly conducting walls under the action of a periodic pressure gradient is studied. An exact solution of the governing equations for the fully developed flow is obtained in a closed form. The expression for the shear stress at the upper plate is also derived. The solutions valid for vanishing and small finite magnetic Prandtl number are derived from the general solution. The asymptotic behavior of these solutions is analyzed, for large values of the frequency parameter […], to gain some physical insight into the flow pattern. It is found that a magnetic field tends to retard the fluid flow in both the primary and secondary flow directions whereas oscillations and rotation tend to accelerate it in both the directions. The magnetic field reduces primary and secondary induced magnetic fields whereas oscillations and rotation have reverse effect on it. The magnetic field reduces the primary as well as secondary shear stress at the upper plate […] whereas oscillations and rotation tend to increase it.

5

Hall effects on oscillatory Couette flow

Ghara N., Maji S. L., Das S., Jana R. N.

International Journal of Applied Mechanics and Engineering

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2011

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Vol. 16, no 4

1005-1020

EN

Hall effects on the oscillatory Couette flow between two horizontal parallel plates are studied. One of the plate is at rest and the other one oscillates in its own plane. The effects of Hall and frequency parameters on the velocities and the shear stresses for the steady and unsteady flows are analyzed. It is found that the shear stresses at the M stationary plate due to the unsteady primary and secondary velocities have a phase lag over the plate oscillations for those values of the Hall parameter m, Hartmann number and the frequency parameter , we have considered.