Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 6

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

Search:
in the keywords:  45.10.-b
help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Investigation of Effects of Parameters in Element-Free Galerkin Method for Bending Analysis of Mindlin-Reissner Plates

100%
Bozkurt Ö., Barbar M., Özbek Ö.
Acta Physica Polonica A
|
2015
|
vol. 128
|
issue 2B
B-208-B-210
EN
The element-free Galerkin method is one of the most widely used meshfree method in solid mechanics due to its simplicity and high convergence rate. However, it has some selectable parameters that affect the accuracy and convergence. The parameters can be listed as size of support domain, number of monomials, type of weight function, number of integration points in a background cell and value of penalty coefficient. The effects of these parameters on the accuracy of the element-free Galerkin method solution of the Reissner-Mindlin plate bending are investigated. A number of case studies with regular and irregular node distributions are solved. The displacement and moment values at critical points are compared with exact solutions. It is shown that the selectable parameters have to be carefully selected especially for the analysis of moments.
2
Content available remote

Determining the Distribution of Values of Stochastic Impulses Acting on a Discrete System in Relation to Their Intensity

63%
Jabłoński M., Ozga A.
Acta Physica Polonica A
|
2012
|
vol. 121
|
issue 1A
A-174-A-178
EN
In our previous works we introduced and applied a mathematical model that allowed us to calculate the approximate distribution of the values of stochastic impulses η_{i} forcing vibrations of an oscillator with damping from the trajectory of its movement. The mathematical model describes correctly the functioning of a physical RLC system if the coefficient of damping is large and the intensity λ of impulses is small. It is so because the inflow of energy is small and behaviour of RLC is stable. In this paper we are going to present some experiments which characterize the behaviour of an oscillator RLC in relation to the intensity parameter λ, precisely to λ E(η). The parameter λ is a constant in the exponential distribution of random variables τ_{i}, where τ_{i} = t_{i} - t_{i - 1}, i = 1, 2, ... are intervals between successive impulses.
3
Content available remote

Determining the Distribution of Stochastic Impulses Acting on a High Frequency System through an Analysis of Its Vibrations

63%
Jabłoński M., Ozga A., Korbiel T., Pawlik P.
Acta Physica Polonica A
|
2011
|
vol. 119
|
issue 6A
977-980
EN
The motion of an oscillator with damping excited by impulses has the form $ξ_t = \frac{1}{\sqrt{a^2 - b^2}} \sum_{0
4
Content available remote

Distribution of Stochastic Impulses Acting on an Oscillator as a Function of Its Motion

63%
Jabłoński M., Ozga A.
|
EN
In previous papers formulas have been derived describing distribution of a random variable whose values are positions of an oscillator at the moment t, which, in the interval [0, t], underwent the influence of stochastic impulses with a given distribution. In this paper we present reasoning leading to an opposite inference thanks to which, knowing the course of the oscillator, we can find the approximation of distribution of stochastic impulses acting on it. It turns out that in the case of an oscillator with damping the stochastic process ξ_{t} of its deviations at the moment t is a stationary and ergodic process for large t. Thanks to this, time average of almost every trajectory of the process, which is the n-th power of ξ_{t} is very close to the mean value of ξ_{t}^{n} in space for sufficiently large t. Thus, having a course of a real oscillator and theoretical formulae for the characteristic function ξ_{t} we are able to calculate the approximate distribution of stochastic impulses forcing the oscillator.
5
Content available remote

Influence of Cavity Design on Stress Distribution in Second Premolar Tooth Using Finite Element Analysis

63%
Parlar Z., Gökçek E., Yildirim K., Kahyaoglu A.
Acta Physica Polonica A
|
2017
|
vol. 132
|
issue 3
949-953
EN
The objective of this study is, using finite element analysis, to design cavity geometry, to minimize risk of the fraction and cracking in second premolar tooth. To avoid possible tooth fracture, proper cavity geometry can be designed, to reduce the effect of masticatory forces. Premolar tooth was chosen due to its least strength in comparison to other type of teeth. In literature, there was insufficient study on using finite elements methods to investigate restorated premolar teeth. A healthy premolar tooth was scanned to obtain 3D model of it, to perform finite elements analysis. The validation was performed based on existing experimental data. According to stress distribution, three different cavity geometries were designed using composite resin and ceramic as a restoration material. It is observed that the amount of stress acting on tooth is diminishable with regard to analysis results. Hence, proper cavity geometry and material were found to minimize the risk of tooth fracture.
6
Content available remote

First-Principles Study of Structural, Elastic and Mechanical Properties of Zinc-Blende Boron Nitride (B3-BN)

38%
Daoud S., Loucif K., Bioud N., Lebgaa N.
Acta Physica Polonica A
|
2012
|
vol. 122
|
issue 1
109-115
EN
First principles study of structural, elastic properties and anisotropy effect on the mechanical parameters of the zinc-blende boron nitride has been performed using the pseudopotential plane wave method based on density functional theory with the Teter and Pade exchange-correlation functional of the local density approximation. The equilibrium lattice constant, molecular and crystal densities, bond length, the independent elastic constants, bulk modulus and its pressure derivatives, compressibility, shear modulus, internal strain parameter, isotropy factor, compliance constants, the Debye temperature, Young's modulus, Poisson's ratio, the Lamé constants and sound velocity for directions within the important crystallographic planes of this compound are obtained and analyzed in comparison with the available theoretical data reported in the literature.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.