Wyniki wyszukiwania - BazTech

1

Research of dynamic processes in an anvil during a collision with a sample

Pyr'yev Yuriy, Penkul Andrzej, Cybula Leszek

Acta Mechanica et Automatica

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2023

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Vol. 17, no. 1

104--111

EN

The paper concerns modelling the dynamics of the contact system of the tested sample with an elastic half-space (anvil) during their collision. The original elements in the paper include the proposed general approach to solving the problem of contact dynamics. The presented approach consists in determining the force of impact on the sample during the collision and the joint solution of the problem for the tested sample and the problem for an elastic semi-space under the conditions of the assumptions of Hertz's theory. The resulting interaction forces allow the determination of displacements and stresses.

2

Magneto-thermoelastic problem in the context of four theories under influence of laser pulse and gravity field

Abo-Dahab Sayed, Abd-Alla Abdelmooty, Alqarni Abdelkalk

Archives of Thermodynamics

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2020

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Vol. 41, no 1

31--66

EN

The paper is devoted to study the effect of gravity, magnetic field and laser pulse on the general model of the equations of generalized thermoelasticity for a homogeneous isotropic elastic half-space. The formulation is applied under four theories of generalized thermoelasticity: the coupled theory, Lord-Schulman theory, Green-Lindsay theory as well as Green-Naghdi theory. By employing normal mode analysis, the analytical expressions for the displacement components, temperature and the (mechanical and Maxwell’s) stresses distribution are obtained in the physical domain. These expressions are also calculated numerically and corresponding graphs are plotted to illustrate and compare the theoretical results. The effect of gravity, magnetic field and laser pulse are also studied and displayed graphically to show the physical meaning of the phenomena. A comparison has been made between the present results and the results obtained by the others. The results indicate that the effects of magnetic field, laser pulse and gravity field are very pronounced.

3

Generalized thermoelastic interactions due to an inclined load at a two-temperature half-space

Abouelregal A. E., Zenkour A. M.

Journal of Theoretical and Applied Mechanics

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2016

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Vol. 54 nr 3

827--838

EN

The article presents a two-temperature theory to study the thermally insulated stress-free surface of a thermoelastic solid half-space due to an inclined load. The inclined load is a linear combination of a normal load and a tangential load. The normal mode analysis has been employed to solve the present problem. Variations of conductive and thermodynamic temperatures, displacements, and stresses distributions with the horizontal distance have been presented graphically. Some comparisons have been made to estimate the effects due to the two-temperature parameter and the inclination angle on the field quantities. Results of earlier works have been deduced from the present investigation as special cases.

4

Półprzestrzeń sprężysta jednorodna i z dodatkową wierzchnią warstwą sprężystą jako modele mechaniczne nawierzchni drogowej

Nagórska M., Nagórski R.

Autobusy : technika, eksploatacja, systemy transportowe

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2013

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R. 14, nr 3

79-87

PL

W artykule przedstawiono wyniki obliczeń porównawczych przemieszczeń i odkształceń na podstawie różnych modeli mechanicznych nawierzchni drogowych podatnych: półprzestrzeni sprężystej wielowarstwowej odzwierciedlającej warstwy konstrukcyjne nawierzchni i jej podłoże gruntowe, dwóch wariantów modeli uproszczonych w postaci sprężystej półprzestrzeni jednorodnej z dodatkową sprężystą warstwą wierzchnią odzwierciedlającą wszystkie warstwy konstrukcyjne (w wariancie pierwszym) lub tylko warstwy asfaltowe (w wariancie drugim) oraz modelu zastępczego (uśrednionego) w postaci jednorodnej półprzestrzeni sprężystej.

EN

The paper presents the results of comparative calculations of deformations and strains on the basis of different mechanistic models of road pavement: multi-layer elastic half-space that reflects the structure and subsoil, two variants of simplified models in the form of a homogeneous elastic halfspace with an additional elastic cover layer that reflects all the construction layers (in the first variant) or only asphalt layers (in the second variant) and a homogenized model (averaged) in the form of a homogeneous elastic half-space.

5

Eigenvalue approach to two dimensional problem of generalized thermoelasticity for a half - space with body-force

Lahiri A., Das B.

International Journal of Applied Mechanics and Engineering

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2012

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Vol. 17, no. 2

419-437

EN

The theory of generalized thermoelasticity is applied to a two-dimensional problem for a half-space under the action of body forces. The surface is stress free with thermal shock. Double integral transforms (Laplace transform for time variable and Fourier transform for space variable) are used and the resulting equations are written in the form of a vector-matrix differential equation. The solution of the vector-matrix differential equation in the transformed domain are obtained by eigenvalue approach. The inversion of the Laplace transform is carried out numerically by the Bellman method and computations are done by Mathematica software. Finally, numerical computations of the temperature distribution, displacement and stress components are made and represented graphically.

6

Reflection and transmission of plane SH-wave at an interface between two different self-reinforced elastic half-spaces

Chaudhary S., Rani R.

International Journal of Applied Mechanics and Engineering

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2011

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Vol. 16, no 4

977-988

EN

Reflection and transmission of plane SH-waves interacting at an interface between two self-reinforced elastic half-spaces is investigated. The expressions for reflection and transmission coefficients are obtained in a closed from and are computed for different values of non-dimensional self-reinforced elastic parameters and presented graphically. The problem studied by Bullen and Bolt (1985.p.143), when both the self-reinforced elastic solid half-spaces M1 and M2 are isotropic elastic and the SH-wave is made incident at an interface has been reduced as a special case of our problem.

7

Complementary pair of quasi-antiorders

Crvenkovic S., Mitrovic M., Romano D. A.

Reports on Mathematical Logic

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2010

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Vol. 45

135-142

EN

The aims of the present paper are to introduction and investigate of notions of complementary pairs of quasi-antiorders and half-space quasi-antiorder on a given set. For a pair alfa and beta of quasi-antiorders on a given set A we say that they are complementary pair if alfa union beta =not equal to=A and alfa intersection beta = empty set. In that case, alfa (and beta ) is called half-space on A. Assertion, if alfa is a half-space quasi-antiorder on A, then the induced anti-order theta on A/(alfa union alfa -1) is a half-space too, is the main result of this paper.

8

Bessel potentials, Green functions and exponential functionals on half-spaces

Byczkowski T., Ryznar M., Byczkowska H.

Probability and Mathematical Statistics

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2006

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Vol. 26, Fasc. 1

155--173

EN

The purpose of the paper is to provide precise estimates for the Green function corresponding to the operator (I—Δ)α/2, 0 <α< 2. The potential theory of this operator is based on Bessel potentials Jα=(I—Δ) -α/2. In probabilistic terms it corresponds to a subprobabilistic process obtained from the so-called relativistic a-stable process. We are interested in the theory of the killed process when exiting a fixed half-space. The crucial role in our research is played by (recently found) an explicit form of the Green function of a half-space. We also examine properties of some exponential functionals corresponding to the operator (I—Δ) α/2.

9

Minimum weight design of vertically vibrating 3-D machine foundation coupled to layered half-space

Sienkiewicz Z., Wilczyński B.

Computer Assisted Mechanics and Engineering Sciences

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1998

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Vol. 5, nr 4

373-387

EN

Dynamic optimization problem for a machine rigid block foundation on an inhomogeneous soil is considered. The soil deposit under the base of block corresponds to a layer with linearly varying properties overlying a uniform half-space. Furthermore, the block may be surrounded by a backfill. The optimal designs of a vertically excited rectangular block foundation are found by iterative application of a sequential linear programming for a number of rationally inhomogeneous supporting media as well as for a uniform half-space. It illustrates the problem of adequate modelling of the nature of the soil profile and provides an insight into the action of the soil-foundation-machine system from the point of view of the long-term satisfactory performance and safety.