×

You are using an outdated browser Internet Explorer. It does not support some functions of the site.

Recommend that you install one of the following browsers: Firefox, Opera or Chrome.

Contacts:

+7 961 270-60-01
ivdon3@bk.ru

  • The impact of mineral micro filler additives on the properties of fine-grained concrete

    In this paper, the influence of different types of fine ground mineral fillers. Additives introduced in the composition of fine-grained concrete. Selected effective filler based on the local opal-cristobalite of the flask. Set its optimal dosage. As a binder used Portland cement CEM I 42,5 R (Turkey). As the filler used local fine sand with a fineness modulus of Mк 1,12. As additives used opal-cristobalite of the flask, waste slag, ceramsite dust, ground quartz sand. The optimum number of flasks of 0.3 – 0.6 m.p. The use of the flask was increased about 2 times the strength of concrete in bending. The compressive strength increased by 40%.

    Keywords: fine-grained concrete, fine ground mineral filler

  • Non-linear heat conduction problem for radiation-heat shield of nuclear reactor

    The stationary heat conduction problem for radiation-heat shield of the reactor nuclear power plant based on domestic sources of heat was solved. We took into account the dependence of the thermal conductivity of the concrete on the temperature, which leads to nonlinear problem. The solution is performed using the finite element method in combination with the method of successive approximations. We used the simplex triangular elements. The problem was solved in axisymmetric formulation. As a design scheme we used a rigidly clamped at the base thick-walled cylinder. It was found that the inclusion of thermal conductivity depending on the temperature leads to a slight (2.5%) increase of temperature in core of the construction.

    Keywords: thermal conductivity, finite element method, the steady-state temperature field, radiation-heat shield, thick-walled cylinders

  • Calculation of reinforced concrete arch with the creep of concrete

    The article presents basic equations for reinforced concrete elements that are experiencing bending moment and axial force, taking into account the creep of concrete. The stress-strain state of reinforced concrete statically determinate three–hinged arch is investigated on the basis of these equations. Also for this task we gained the resolving equations of finite element method and compared the numerical-analytical calculation with the numerical performed using the finite element method to the arch loaded with a uniformly distributed load and having the shape of a circular arc. The calculations used viscoelastic model, according to which the total deformation is the sum of concrete elastic deformation and creep. We consider a rectangular cross section with symmetrical reinforcement. It is shown that because of creep stress redistribution between concrete and reinforcement arises.

    Keywords: finite element method, the creep of concrete, viscoelasticity, reinforced concrete arch, the stress–strain state.

  • Determination of long-term critical loads for compressed polymer rods with nonlinear creep

    The article provides information about method of sustainability calculation of compressed polymer rods taking into account nonlinear creep . As the law of the relationship between stress and strain is used nonlinear equation of Maxwell-Gurevich. Derived from the analysis of the resolving equations with time tends to infinity, we obtain an expression for a long critical force in the case of constant rigidity of the rod.

    Keywords: nonlinear creep, rod, stability, Maxwell-Gurevich, finite difference method, long critical force, relaxation viscosity, viscoelasticity, high elasticity modulus.

  • Ways of increasing the efficiency of forest machine roll-over protective structure.

    This article deals with the way of increasing the energy absorption capacity of forest machine cabin roll-over protective structure. The ability to absorb certain amount of potential energy during deformation is the one of basic requirements to cabin of a forest machine. The risk of injures to the operator is reduced by using two-way energy-absorbing cab support in the construction of roll-over protective structure. The protective effect is attained by plastic strain of cab support elements, that provides operator’s protection during an accidental roll-over. The article presents the design of the cab support, describes its functional principle in the event of an emergency.

    Keywords: roll-over protective structure, forest machine, energy-absorbing support, construction, plastic strain

  • Flat axisymmetric problem of thermoviscoelasticity for polymer cylinder

    The technique of determining the stress-strain state of the polymer thick cylindrical shells in flat tension conditions with effects of temperature and creep deformation. As the law of the relationship between stress and strain is used nonlinear equation of Maxwell-Gurevich. Solution is performed numerically by finite element method.

    Keywords: nonlinear creep, cylinder, the Maxwell-Gurevich equation, finite element method, relaxation viscosity, viscoelasticity, high elasticity modulus, plane stress and temperature.

  • Calculation of reinforced concrete frame buildings, taking into account the impact of emergency in the time domain

    The article examines the calculation of a building frame on the spatial plate-core scheme, taking into account the impact of emergency in the time domain by using the Finite Element Method (FEM). The calculation was performed considering the failure of the loaded columns of the building. The article includes the value added tax analyse and the conclusion about the protection of buildings against progressive destruction of.

    Keywords: The calculation of reinforced concrete frame buildings, the impact of emergency in the time domain, Finite Element Method (FEM), the failure of the loaded columns ,the value added tax analyse, the protection of buildings against progressive destruction

  • The estimation of load-carrying capacity of forest machine roll-over protective structure from the point of fracture mechanics

    This paper deals with the application of main fracture mechanics equations for estimation of cracklike defects influence over forest machine roll-over protective structure survival. The definition of breaking points in protective structure was done by finite elements method. Stress intensity factor was defined as the estimation criterion. It relate the local mechanical state near the crack tip to macroscopic characteristics such as the geometry of a body and loading, and enable to give simple description of crack growth process. The stress intensity was estimated by finite element method. Breaking lengths were calculated for different types of cracks: through, edge and semielliptic. As shown, the presence of cracklike defects, even small length, rather reduces the level of breakdown load.

    Keywords: fracture mechanics, cracklike defect, finite element method, roll-over protective structure, breakdown load

  • Comparative analysis of mathematical models of sustainability glubokorazryhlennyh saturated with water slopes

    In the development of resource-saving technologies of processing of sloping lands, which provides deep loosening, it was developed and patented a new method of processing initially resistant sloping lands, aimed at subsurface moisture accumulation on the slopes. A mathematical model of steady state, designed to study the issue of stability of surface soil moisture saturation. A new method of calculating the limit conditions for holding the treated soil moisture saturation on the slope. Define the tasks of the theoretical calculation of the balance of forces applied to the considered solids on an inclined surface. Analysis of the results revealed that the treated layer will be in a state of stable equilibrium.

    Keywords: steady state equilibrium conditions, the system deformers, traction, breaking up the area

  • The analysis of a personnel management system territorial generating the companies of the Rostov region and an assessment of their efficiency

    The analysis of the existing personnel management system of the territorial generating companies of the Rostov region, on the example of JSC LUKOIL-Rostovenergo is carried out. The main directions of a personnel management system are considered: opportunities for professional development and career advance; package of social payments and privileges; moral incentive. Procedure of carrying out a self-assessment of workers and a technique of definition of annual awarding of each worker of one of the territorial generating companies is considered: criteria of carrying out a self-assessment, sequence of carrying out and a formula for calculation of total point for calculation of indicators of awarding. In the conclusion expediency and efficiency of carrying out of this sort of actions of the employees of JSC LUKOIL-Rostovenergo directed on human resource management is analysed.

    Keywords: power industry, human resource management, young specialists, Rostov region, adaptation of the personnel, social payments

  • Assessment of economic effect for consumers at installation of the automated metering stations and regulations of thermal energy

    Introduction of the automated metering stations and regulation (AUU) located directly in the heated building besides creation of comfortable conditions indoors leads to decrease in consumption of thermal energy. In work the assessment of economic effect for inhabitants of an apartment house after installation of pogodozavisimy regulation is carried out.

    Keywords: individual thermal point, the automated metering station and regulations, pogodozavisimy regulation, decrease in heatconsumption, economic efficiency

  • By setting the task of creating intelligent process control systems to extinguish forest fires

    Showing promise of creating intelligent process control systems to extinguish forest fires and robotics such processes. Particular attention is paid to the need to equip members of intelligent devices forest fire calculations. The system control devices classified as a homogeneous group which solves the problem of localization and suppression of forest fires in the face of opposition environment.

    Keywords: intelligent system, forest fires, fire brigades, robotics, fire

  • Optimization of the form of step-prismatic bended beam

    We obtained the solution of the optimization problem for the step-parallel beam with constant width of the cross-section. The problem was solved by minimizing the strain energy while the volume of beam is constant. The solution was made for the case of simple support at the ends and evenly distributed along the length load. We introduced the parameter α, which is the ratio of height of the average part to a height of side parts. The optimal value of α was found. At this value the stiffness of the beam is maximum at constant volume. The obtained beam of maximum stiffness is not equal strength.

    Keywords: optimization, speed-prismatic beam, the strain energy, variable stiffness, minimum

  • Optimization of geometrical parameters of gable rectangular beam

    We solved the problem of optimizing the gable beam by minimizing the strain energy at constant volume. The problem reduced to an integral equation for determining the optimum angle of the beam. This equation was solved numerically by the method of bisection. Integral was calculated using the method of trapezoids. Solution was made in software package Matlab. The optimum angle depends on the width of the cross section b, and the volume of the beam. It was found that with increasing of width of the cross section the optimum tilt angle decreases. Also the volume increases by increasing the width of the beam.

    Keywords: optimization, gable beam, strain energy, variable rigidity, minimum volume, method of bisection

  • The overall stability of a spherical shell coating of an object "Winter garden" Technopark of the RGSU

    The article examines the calculation of spherical shell coating on the overall stability under load. The calculated values of deformations in the vertical and horizontal plane. After the calculation of the conclusions and recommendations are given to conduct the necessary engineering activities to ensure the sustainability of the building.

    Keywords: spherical shell; overall stability; arch farm; calculation of the building frame; finite element method

  • "The calculation of the hostel building of Technopark, Rostov state university of civil engineering (RSUCE) using various models of the base "

    In article influence of various models of the soil base at calculation of the frame building of the hostel of RSUCE on functionality and operational characteristics of designs is considered. The final-element (FE) model of object is made and calculation in a program complex is executed. By results of calculation the analysis of the intense-deformed condition of the building and the basis is made. For research of influence of various models of the soil basis on the intense-deformed condition of the building models of the Pasternak and Vinkler and model taking into account a pliability of support are considered. The analysis found that the use of models taking into account the pliability of supports are more practical. This model allows the most accurate to see the interaction of building structures with elastic soil base and can be used in the real design.

    Keywords: the core stiffness, the diaphragm stiffness, the structural design, the finite-element model, the stress-strain state, the base model, support yield, the coefficient of the bed, the intensity of reinforcing, orthotropy

  • Stability of concrete arch in creep

    The phenomenon of buckling under the creep of concrete arches was investigated. Solution of the problem carried out by means of the finite element method. To analyze the stability we used Newton-Raphson method. It has been established that there is a long-term critical load, beyond which the growth of the deflection has not fading character. As the equation of the relationship between the creep deformation and strains we used viscoelastoplastic hereditary model of aging concrete. To determine the creep strain we used a linear approximation with respect to time. It was found that the long critical load for considered arch was in 1.44 times lower than the instant critical load.

    Keywords: reinforced concrete arch, stability, creep, geometric nonlinearity, finite element method, Newton-Raphson method

  • Valuation quality of water by hydrochemical indicators in water intakes places of Taganrog.

    The main contence of this article is a valuation quality of water in water intakes places of Taganrog. A specific combinatory index of pollution of water is used for valuation quality. In this article is considered dynamics of the main polluting substances around water intakes.

    Keywords: maximum permissible concentration specific, combinatory index of water pollution, quality of water, critical indicators ofwater pollution, sulfates

  • The development of nodal connections for cross structures of buildings

    In the article, we prove the efficiency and versatility of the method of the cross structures of the building mounting by bolting junction of angles rigidly fixed to the vertical and horizontal walls of the rods. The advantage is the ability to apply this type of mounting in dynamically loaded constructions.

    Keywords: Node joints, cross design, spatial frames of buildings and structures, tubular profiles of rectangular, concrete pipe elements

  • Territorial branding as instrument of development of the recreational complex of the region

    In article problems of formation, positioning and advance of a brand of a recreational complex of the region as strategic instrument of development are considered; specifics, regularities and interdependence of basic concepts of territorial branding of the recreational region come to light.

    Keywords: territorial branding tool development, recreational complex , region, specific , patterns

  • Increase of ballistic characteristics of small arms due to application of the upgraded Gerlakh's scheme

    The interrelation between ballistic, design and power characteristics for Gerlakh's scheme in comparison with the basic shooting weapon rifle of Dragunov is investigated. Recommendations are made on a sleeve and the boss, applied at design.Preliminary outline study of a prototype is executed.

    Keywords: muzzle energy, strength, pressure, velocity, momentum, ballistics

  • Modern ways of improving energy efficiency of residential buildings

    The paper deals with the energy efficiency of residential buildings. It describes the basic criteria for evaluating energy efficiency of residential buildings. It reviewes basic technological and engineering resources solving problems of energy efficiency. Particular attention is paid to the comprehensive measures to ensure the buildings high-class energy efficiency.

    Keywords: energy efficiency, design, heating, water, electricity, construction, heat loss, air conditioning, heat transfer agent

  • Sufficient Conditions of Equilibrium Stability of Instantly Stiffened Hinged-Rod Systems

    The article proves the equilibrium stability of hinged-rod system made of elastic material in pretension state for the case, when characteristics of some special matrix is not negative and certain amount of zero numbers concludes it. The author estimates the possible number of compression and tie bars of the system. The article identifies the number of parameters, the change of which allows fulfilling sufficient conditions of existence of the system under research.

    Keywords: equilibrium stability, hinged-rod system, elastic material, topological construction, instantaneous lockstep, bracings.

  • Comparison of finite element modeling and analytical approach results for oscillating rod structure with crack

    the paper considers the comparison of natural modes for the first and second transverse oscillation modes obtained by numerical simulation and finite element package of analytical calculation of the core model with an elastic element based on the application of the Euler-Bernoulli hypothesis. The analysis compared waveforms for different values of the defect shows their satisfactory agreement.

    Keywords: rod design, vibrations, defect, finite element modeling, analytical modeling, waveform

  • Comparing various kinds of game formulations of purpose and non-purpose resource using problem

    In this article the problem of purpose and non-purpose resource use is considered. In the system there are two elements each of which has some resource quality and he must allocate his own resource among public and private interests. Elements of the system may be equal one to other or they may be connected by leading-subordinating relationship. Besides, elements can enter into the coalition. By combining all various situations we obtain four possible cases. The first is when both elements are equal and don’t enter into the coalition. In this case there is a game in normal form in which Nash-equilibrium is found. The second is when both elements are equal and form the coalition. In this case Pareto-optimal set is found. The third is when one element subordinates to the other element without their union into the coalition. In this situation there is a hierarchical Г1 or Г2 game in which Stackelberg equilibrium is found or the Germeyer’s theorem is applied. The forth is when one element subordinates to the other element with their union into the coalition. The aim of investigation was to compare the influence of hierarchy, possible cooperation and different types of public and private activity functions of elements on the performance of purpose commitments. The research has shown that equality of elements is the better than hierarchy. Besides, elements assign more resources to the public purposes if they form the coalition.

    Keywords: purpose using, non-purpose using, hierarchical system, equal players, player cooperation, private activity function, public activity function, Stackelberg equilibrium, Nash eqilibrium, Pareto-optimal set