Wyniki wyszukiwania - Biblioteka Nauki

1

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

100%

Sienkiewicz Z. , Wilczyński B.

Computer Assisted Mechanics and Engineering Sciences

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1998

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tom 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.

2

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

88%

Abo-Dahab S. , Abd-Alla A. , Alqarni A.

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tom 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

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

75%

Pyr'yev Y. , Penkul A. , Cybula L.

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tom 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.

4

Complementary pair of quasi-antiorders

75%

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

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tom 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.

5

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

63%

Lahiri A. , Das B.

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2012

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tom 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

63%

Chaudhary S. , Rani R.

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tom 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.