Vol 19, No 9.2 (2013)

Articles

DECOMPOSITION OF MULTIRATE DYNAMIC SYSTEMS WITH SMALL DISSIPATION

Voropaeva N.

Abstract

We consider singularly perturbed differential systems which describe the dynamics of manipulator with flexible joints in conditions of small dissipation. The existence of decoupling transformation which converts original multirate system to "block triangular" form with independent slow subsystem. Decoupling transformation is constructed as asymptotic series.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):5-10
pages 5-10 views

ON CONSTRUCTION OF PROGRAM PSEUDO-RANDOM NUMBERS GENERATORS ON THE BASIS OF DYNAMIC SYSTEMS IN DETERMINISTIC CHAOS MODE

Gerasimov L.

Abstract

In this work possibilities of program modelling of deterministic chaos mode are investigated. The research is carried out on the example of program model of Van-der-Pol oscillator. nist statistical tests suite is used for the evaluation of cryptographic properties of received generator of pseudo-random numbers.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):11-18
pages 11-18 views

HOPF BIFURCATION IN THREE-DIMENSIONAL SIRS-MODEL WITH DIFFUSION

Kravets P.

Abstract

In this paper, modified 3D epidemiologic SIRS model with the so-called saturation incidence is considered. In the course of research the considered model was enlarged by means of adding spatial constituent and diffusion process. The aim of the work is to prove the existence of spatial heterogeneous periodic solutions in the system that takes place when bifurcation of periodic solutions happens not only along temporal but spatial variable and to simulate them numerically.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):19-24
pages 19-24 views

DEVELOPMENT OF METHOD OF e-LAYER FOR FINDING INTERVAL ESTIMATES OF QUASIDETERMINED PROCESSES

Suchkova L., Yakunin A.

Abstract

In the paper the basic regulations of method of е-layer are presented and on their basis the evaluation of interval estimations of parameters of modelling functions of quasidetermined processes is considered. As examples of modelling functions polynomials of the first and second order are chosen. The reduction of е-area in space of parametres at processing of samples in signal realisation is shown.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):25-30
pages 25-30 views

EFFECTS OF DAMAGE FIELD ON THE CRACK-TIP STRESS FIELD IN NON-LINEAR MATERIAL

Fedina M.

Abstract

Based on experimental data it is supposed that the boundary of the area in which the process of accumulation of damages takes place, is semiellipse and beams that are parallel to the edges of the crack. Setting by this hypothesis the form of area of the process, asymptotic decompositions of component of tensor of strain and damage are defined.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):31-36
pages 31-36 views

OPERATOR METHOD FOR THE STUDY OF SMALL OSCILLATIONS IN SYSTEMS WITH AFTEREFFECT

Yumagulov M., Yakshibaeva D.

Abstract

This paper proposes operator method for the study of effect of appearence of small oscillations in systems with aftereffect.The method leads to new sufficient features of Andronov - Hopf bifurkation and allows to obtain approximate formulas for emerging decisions. As an application, we consider the problem of bifurcation points of Hutchinson - Wright equation.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):37-44
pages 37-44 views

PLASTICITY CONDITION CONNECTED WITH LEVEL LINES OF STRAIN STATE SURFACE FOR DIFFERENT DEFORMATION PROCESSES

Bukhanko A.

Abstract

On the basis of the theory of plastic flow the peculiarities of application of plasticity condition connected with level lines of strain state surface for work-hardening incompressible rigid-plastic body at different stressed states realized in the context of plane and axisymmetric strain, plane stressed state are considered. Comparison of the proposed condition with plasticity conditions of Mises and Tresca is carried out on the basis of construction of yield curves in deviatoric plane and in planes corresponding to certain stressed states. It is shown that the proposed plasticity condition describes plastic flow on the edge of Tresca prism in conditions of axisymmetric deformation.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):43-54
pages 43-54 views

TASK ON INDENTATION OF SMOOTH PUNCH OF AN ARBITRARY FORM IN PLANE VIEW IN HARD PLASTIC HALF-SPACE

Vlasova I.

Abstract

In the work the general properties of equations of spatial problem of the theory of ideal plasticity in the condition of Treska plasticity and stressed state that correspond to the ridge of surface of fluctuation are viewed. Singular lines in hard plastic space and solutions in the neighborhood of a singular line that are similar to the expansion in beam series are viewed. On the basis of the developed theory the boundary problem appearing at indentation of punch with smooth basis in a certain plastic body which in the simplest case is a half-space is solved.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):55-62
pages 55-62 views

NUMERICAL PHOTOMECHANICS: NUMERICAL PROCESSING OF PHOTOELASTICITY EXPERIMENTS AND ITS APPLICATION TO THE PROBLEMS OF FRACTURE MECHANICS PROBLEMS

Gerasimova T., Lomakov P., Stepanova L.

Abstract

On the basis of photoelasticity method the experimental study of near crack tip stressed strain state in specimens under mixed loading conditions is performed. Carried out experimental investigation allows to obtain coefficients of full asymptotic expansions of stress and displacement fields in the vicinity of the crack tip and alos to find coefficients of highest approach in Williams full asymptotic expansion.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):63-73
pages 63-73 views

DEFINITION OF STAGNANT ZONE OF FLOW OF VISCOUS INCOMPRESSIBLE MICROSTRUCTURAL LIQUID BETWEEN COAXIAL CYLINDERS IN THE PRESENCE OF PRESSURE GRADIENT

Egorov M.

Abstract

In this work mathematical modeling of flow of viscous liquid between coaxial cylinders in the presence of homogeneous structure and pressure gradient. Problem definition in the rate of movement is formulated. Finite - difference scheme is received. Numerical computation is received. The geometrical dimensions of zone of liquid flow with low speed are shown.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):74-79
pages 74-79 views

APPLICATION OF SPECKLE INTERFEROMETRY FOR THE INVESTIGATION OF VIBRATIONS AND STATIC DEFORMATIONS OF ELEMENTS OF ENERGY INSTALLATIONS

Zhuzhukin A.

Abstract

The article deals with the development of digital speckle interferometer with superimposed bundles and speckle modulated reference wave for the study of vibration characteristics and deformation displacements of elements of energy installations excited by statistic loadings. It is experimentally established that at vibration studies thanks to the possibility of using in optical scheme of digital camera in speckle interferograms obtained with the use of interferometer showed that dispersion of speckle noise is from 2.5 up to 3.2 times lower than in speckle interferograms obtained with the traditionally used interferometers with separated bundles and smooth reference wave.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):80-86
pages 80-86 views

LOAD DEVICE FOR TESTING MOBILE DIGITAL SPECKLE INTERFEROMETERS OF DEFORMATIVE DISPLACEMENTS

Zhuravlyov O., Komarov S., Sergeev R.

Abstract

The problem of working out and creation of verification load device for testing mobile digital speckle-interferometers with the current-wave laser, that provides definition of normal deformation displacements is solved. The analytical expression linking difference in phase of interference fields of strained and initial states of object with an offset value of points of its surface. The results of investigation of strains of plates with different requirements of attaching and loading are given.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):87-96
pages 87-96 views

ASYMPTOTICS OF STRESS AND CONTINUITY FIELDS NEAR A FATIGUE GROWING CRACK IN A DAMAGED MEDIUM IN CONDITIONS OF STATE OF PLANE STRESS

Igonin S., Stepanova L.

Abstract

In the paper asymptotic solution to the problem of growth of fatigue crack in conditions of repeated loading in a damaged medium in the coupled elasticity-damage statement of the problem is given. Asymptotic expansions of stress fields and continuity fields in which two summands are retained in asymptotic representation are derived. The problems of determination of amplitude coeffl-cients of obtained asymptotic expansions are discussed.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):97-108
pages 97-108 views

DEVELOPMENT OF DIGITAL SPECKLE OF INTERFEROMETRY FOR THE INVESTIGATION OF DYNAMIC PROCESSES IN REAL TIME

Osipov M., Khokhlov V., Chekmenev A.

Abstract

This paper considers the development of speckle interferometry on the basis of analysis of behavior of intensity of a single speckle for the investigation of dynamic processes in mechanics. Optical scheme for the realization of proposed method of measurement is proposed. The restrictions imposed on the proposed optical scheme are considered. The estimate of the range of measurements of dynamic movements is given. Experimental results of parameters of measurements of surface vibrations are presented.

Vestnik of Samara University. Natural Science Series. 2013;19(9.2):109-117
pages 109-117 views

REVIEW OF INCREMENTAL AND DIRECT METHODS OF DETERMINING ASYMPTOTIC STABILIZED BEHAVIOUR OF INELASTIC STRUCTURES

Turkova V.

Abstract

The review of methods that can be used to define the asymptotic stabilized state of an inelastic structure under cyclic loading is given in the paper. Due to the growth of interest for the knowledge of the asymptotic behaviour of the structure under cyclic loading, incremental (with the use of finite element method) and direct methods (methods of optimal control theory and decomposition of residual stresses in Fourier series) began to develop.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):118-132
pages 118-132 views

MODELING OF DYNAMICS OF FORMATION AND DECOMPOSITION OF GAS HYDRATE PARTICLES DURING THEIR SURFACING IN WATER

Shagapov V., Tazetdinov B.

Abstract

In this paper the process of surfacing of hydrate particles in a liquid is viewed. Typical depths at which hydrate formation is accompanied by bubbling or unchanged hydrate particles and small depths, which are accompanied by decomposition of hydrate ascent particles are singled out. It is assumed that the intensity of hydrate formation and decomposition is determined by the convective heat exchange with the ambient particle of water.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):133-139
pages 133-139 views

THIN-WALLED COVERS WITH SURFACE CRACK DEFECTS IN DUGDALE APPROXIMATION

Yakovlev A.

Abstract

In the work definition of area of possible limiting conditions of thin-walled covers from an ideal elastoplastic material with not through blind fractured defect (scratch) is considered. Areas of possible limiting conditions for scratches of variable depth are considered. Comparison of experimental and theoretical data is given. The problem of determination of limiting extent of defects which at the set level of operational loadings can lead to catastrophic destruction of all construction is solved.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):140-146
pages 140-146 views

HIV EVOLUTION MODEL

Archibasov A.

Abstract

In the paper the results of numerical simulations for Korobeinikov's model of HIV evolution are presented. Based on Tikhonov-Vasilieva method of boundary function the first approximation of the system solutions is realized.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):147-152
pages 147-152 views

MULTI-SCALE STRESS-DEFORMATION STATUS OF POROUS GEOLOGICAL STRUCTURE AS RELATED TO WELL FILTRATION FLOWS

Astafiev V., Kakhidze M., Popkov V., Popkova A.

Abstract

Mono-harmonic junction in the interaction of porous space rock stress in oil/gas saturated reservoirs and averaged hydro-dynamic flows of viscous oil towards wells obtained as a result of innovative decisions in oil industry in general is presented. Within the frames of block homogeneous models of a well through the application of 3D linear theory of wave diffusion along the surface of geophysical emission layer, mathematical statement of asymmetrical filtration challenge with finite velocity of effect is presented. Dispersive ratios for constrained and resonant dissipative structures in a shear layer of viscous-elastic filtration at the edge of a slug of water-oil displacement are given. The redistribution results for the averaged inflow profile of viscous Newtonian filtration into asymmetrical energy-stable stress-deformation status inside the saturated porous media at various constraints: in conditions of enclosed or capillary-clamped boundary and in non-constrained conditions - at the frontier of displacement or with stimulation of water-flood displacement in zones of stagnation is presented.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):153-169
pages 153-169 views

MODELING AND OPTIMIZATION OF MINING WITH MULTIWELL DOUBLY PERIODIC CLUSTERS

Astafiev V., Roters P.

Abstract

The paper is devoted to the productivity of multiwell doubly periodic systems of vertical producing well (multiwell clusters). As cluster, we mean union of several homogeneous elements such that it can be considered as one module with specific features.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):170-183
pages 170-183 views

ABOUT ONE APPROACH TO MODELING OF OPTIMAL CONTROL OF MULTIDIMENSIONAL COMPOSITE LINEAR SYSTEMS

Gorelov Y.

Abstract

The approach to the synthesis of optimal control of multidimensional composite linear system based on solutions of optimal control problems for inclusion in its structure of partial linear systems with scalar controls is considered. Control tasks are reduced to the problem of moments in the L\ space for minimum functionals of the norm type, on minimum maximal Ноlder norms level (with indicators 2 and то) for the vector control composite system.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):184-190
pages 184-190 views

INFLUENCE OF BRAKING OF LAYER ON THE CHARACTER OF THE PROCESS OF FLUID FILTRATION TO THE PRODUCTION WELLS

Karimov N.

Abstract

A model of fluid filtration in the production well in the presence of craks of oil layer is built. These expansions can be both highly permeable and low-permeable and are characterized by the dimensionless ratio of conductivity of Fcd . For different values of Fcd the nature of filtering process is investigated; factor of productivity of the well is defined, an analytical expression for the skin factor, which reflects the influence of fractures on the productivity of the well is obtained.

Vestnik of Samara University. Natural Science Series. 2013;19(9.2):191-195
pages 191-195 views

COMPARATIVE ANALYSIS OF WELL LOCATION SCHEMES AT WATERFLOODING

Kasatkin A.

Abstract

The main aim of this research is the creation of program tool for quantitative and qualitative comparison of different schemes of well location applied at waterflooding: the estimates were supposed to be carried on the basis of solution of the problem of advancement of border of OWC in time. The achieved results may be used for designing of waterflooding of real oilfields. At the heart of program complex lies the model of infinite homogeneous layer of fixed thickness, the surface of which is covered by doubly periodic grating with upstream and blowing wells in their cells. For describing of the process of combined filtration of water and oil modified Weierstrass dzeta-function was used.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):196-207
pages 196-207 views

ON THE METHOD OF SYNTHESIS OF OPTIMAL CONTROL OF SPACECRAFT REORIENTATION DURING SENSING HARDWARE REDIRECTION

Morozova M.

Abstract

The problem of optimal control of spacecraft reorientation during remote earth sensing hardware redirection is considered. Computational algorithm for the approximate solution of the problem is developed. Efficiency of this algorithm is confirmed by the results of the performed modeling.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):208-214
pages 208-214 views

CANARD CURVES IN THE DYNAMIC MODEL OF FOREST INSECT PESTS

Troshkina E.

Abstract

The paper is concerned with the investigation of the model of dynamics of population of caterpillar budworm (Choristoneura fumiferana). The system solutions behavior depending on the parameters values has been investigated, conditions of origination of canard curves have been found.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):215-220
pages 215-220 views

STUDY OF CRITICAL PHENOMENA IN THE MODEL OF ELECTROCHEMICAL REACTOR

Firstova N.

Abstract

The model of an electrochemical reactor by method of singular perturbations and numerical methods is studied. The behavior of solutions of system depending on values of parameters is studied, possibility of bifurcation of Andronov - Hopf and the phenomenon of "canard explosion" is considered.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):221-226
pages 221-226 views

QUANTUM COMPUTATIONS AND ATOM-FIELD ENTANGLED STATES IN JAYNES-CUMMINGS GENERALIZED MODEL

Rusakova M., Bashkirov E.

Abstract

Atom-field entanglement in two-atom system in different initial states in Jay-nes-Cummings model with degenerate two photon transition with dependant from intensity of the field of parameter of atom-field interaction is considered. It is shown that consideration of discontency of parameter of atom-field interaction for some initial states of atoms leads to damping or collapse of instant death of entanglement effect and changes of disentanglement time.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):227-235
pages 227-235 views

THERMAL-CONTROL SYSTEM OF EXPERIMENTAL MODEL OF SPACECRAFT OPTICAL TELESCOPE ASSEMBLY

Tsaplin S., Bolychev S.

Abstract

Software on the base of program package of ANSYS, MathCAD, Zemax for study of influence of thermal factors of space factor on optical characteristics of lens objective of spacecraft is developed. Calculation of non-stationary field of temperature and deformation, output data of lens objective for specific case is carried out.
Vestnik of Samara University. Natural Science Series. 2013;19(9.2):236-243
pages 236-243 views

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