×

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
ivdon@ivdon.ru

  • Modeling of software implementation of labor distribution management

    The paper considers a game-theoretic model for supporting the distribution of labor resources, i.e. To simulate the problem considered in the work, the mathematical apparatus of game theory was used. In this paper, two algorithms for constructing a solution are described and examined in detail for two models of transport tasks used to study the distribution of labor resources: static and dynamic. The authors describe the developed models, and then consider the structure of the solution to the problem. The paper considers a compromise solution in the models of the distribution of labor resources for the transportation problem. An algorithm for finding a compromise set and a description of the structure of the software implementation of models is given. The description of the models is formalized in the field of application to game theory, i.e., a game version of the problem is considered. Interpreting the problem, we consider a system consisting of players. Players in the constructed model strive, in addition to maximizing profits, to achieve a compromise between the participants. The role of compromise will be played by a plan of movement of labor resources, satisfying all participants. As a result, we obtain the transportation problem in a slightly modified formulation. These differences specify a new task and set a goal to solve it.

    Keywords: modeling, analysis, management, software implementation, game-theoretic models, distribution of labor resources

  • Features of using BIM technology in the calculation of reinforced concrete structures

    The article discusses the results of the calculation of monolithic non-slab floors. The authors used software that supports BIM design technology. Models were created in Rewit Sapphire and Lyra-SAPR. The article describes the method of creating computer models. The computational experiment plan and the main parameters of the calculated prototypes are given. A total of four series of samples was calculated. The series differ in the way they create a computer model. In each series, all methods of triangulation that are available for this software package are implemented. To ensure the comparability of results, the step of triangulation in each of the series was taken to be the same: 0.17, 024, 0.4, 0.46, 0.55, 0.67 and 0.86 m. The authors made a comparative analysis of the quality of computer models after they were imported into the PC Lira-SAPR. It has been established that errors are observed when importing schemes from different software systems. Characteristics of the material, the stiffness of the elements and the load are not always transmitted correctly. This circumstance forces to do additional work. Namely, a detailed check of the circuit and its adjustment manually. BIM technology, reinforced concrete, girder-free overlap, reinforcement, triangulation, finite element, reinforcement selection, computational experiment, Rewit, Sapphire, Lira-CAD.

    Keywords: BIM technology, reinforced concrete, girder-free overlap, reinforcement, triangulation, finite element, reinforcement selection, computational experiment, Rewit, Sapphire, Lira-CAD

  • Automation of control of hoisting-and-transport mechanisms in emergency response

    This article presents the results of studies on the possible use of hoisting-and-transport rope complexes in the aftermath of emergency and environmental situations. The advantages of using self-propelled transport and freight carriages based on soft pneumatic bearings for rescue operations are considered. An algorithm is described for a software package designed to automate the process control of a freight-carriage used to lift and move cargo at predetermined coordinates. To implement the functioning of the software package, a processing technique was used for incoming and outgoing data, input and output streams, data collection centers using Java TCP / IP technology. An example of a graphical interface of the software.

    Keywords: software package, control automation, hoisting and transport mechanism, protocol, JAVA, algorithm, environmental consequences, cable system, local coordinates

  • Modeling of the low-pass filter

    Results of modeling and a pilot study of a low-pass filter with a cut-off frequency of 4 GHz are given. Modeling of the filter was carried out in MicrowaveOffice application program package. The experiment was made on the vector analyzer of RXA chains. Results of modeling and an experiment conform to the imposed requirements, namely: - cut-off frequency is 4 GHz; - losses in bandwidth no more than 3 dB; - an obstacle on the second harmonic of cut-off frequency not less than 60 dB; - wave resistance of an input and exit of 50 Ohms.

    Keywords: low-pass filter; cut-off frequency; losses in bandwidth; losses in an obstacle band; modeling; experiment

  • Investigation of the process of thermal conductivity in a plate with internal sources of heat of constant power

    Based on the use of additional boundary conditions (characteristics) and the integral method of heat balance, a numerical and analytical solution of the heat conduction problem for an infinitely extended plate is obtained under symmetric boundary conditions of the third kind with constant internal heat sources in time. Considering the heat flux on the plate surface as a new sought function, a simple analytical form of the specified problem is obtained. Using the proposed approach is possible for solving partial differential equations that do not allow separation of variables.

    Keywords: analytical solution, internal heat sources, non-stationary thermal conductivity, boundary value problem, boundary conditions of the third kind, additional function, integral of heat balance

  • The Paving Slab Market Analysis and Development Prospects in the Rostov Region

    The paving slab market analysis and development prospects for the Rostov Region are given in this article. The market prospects are considered from the point of view of paving slab manufacturers on their participation in government programs of a modern urban environment formation and improvement. The main changes in the product specifications requirements are considered taking into account the enactment of GOST 17608-2017 instead of GOST 17608-91. We analysed the pricing policy of large manufacturers of paving slabs operating in the Rostov Region. Then we also considered the prospects of paving slab sales for municipal projects and in the private segment. We also reviewed the government programs for creation of a comfortable urban environment and their financing in the Rostov Region, as well as cooperation prospects between the municipal government and business in terms of concession agreements. Finally, we defined the main consumer categories for the paving slabs and the consumption structure of the paving slabs market.

    Keywords: paving flag, paving slabs, improvement, modern urban environment, the formation of a modern urban environment, paving

  • Modeling of oscillations under the pulse effect of a multilayer structure in the Ansys complex

    The simulation of a multilayer structure in the finite element Ansys complex is considered. The design consists of 10 layers, each of which has certain specific properties. The model is an imitation of the soil base pavement. We consider the simulation in the form of a simplified, flat statement of the problem. The analysis of the oscillations under impact. The wave field of displacements at a given part of the structure is analyzed. Based on a numerical experiment, an approach to estimating the characteristics of a layer is constructed.

    Keywords: multi-layer construction, vibration diagnostics, simulation, FEM, Ansys, pulse action, dynamics, fluctuations

  • Methods of dealing with fine dust at a construction site in the production of stone installation works

    This article describes the method of dust emission suppression at a construction site. The results of the effectiveness of the developed equipment, fog formation gun, were obtained in the course of full-scale measurements in the course of stone installation works at the construction site in Rostov-on-don. The assessment of the air dustiness of the builder workplace and the degree of impact of the fog formation gun were attended with the statistical dependence of the number of dust particles PM2.5-PM10 . During the analysis, the following factors were studied: the location of the workplace at the construction site, the relative humidity and temperature. During the study, the following conditions were met: the premises were closed; the study was carried out in the process of performing stone installation works. The results of the experiment showed the effectiveness of the fog gun.

    Keywords: environmental safety, fine dust, dust settling, dust suppression, ecology in construction, dust collectors, construction work, air protection, labor protection in construction, dust pollution

  • Model building for the numerical study of the stress-strain state of geomassive when moving a face

    For a numerical study of the stress-strain state of the edge sections of a coal vein under the influence of a mining zone, there is a mathematical model of the geomass deformation processes, which is reproduced in the form of boundary value problems of the theory of elasticity. The problem was solved by the finite element method in a variational formulation, in which the functional was minimized with full potential energy to determine displacements in narrow of elements. Computational experiments were carried out using the author's complex of programs. Based on the results of numerical modeling, recommendations for strengthening the coal target and definitely bearing capacity was developed. The use of the developed mathematical model and software package allows us to design documents at the development stage, to predict the stress-strain state of the geomass in the zone of influence of the underground mining system.

    Keywords: Mathematical model, numerical modeling, computational experiment, software package

  • Crack resistance test of samples from polyethylene pipes

    The article presents the results of testing samples of welded joints of polyethylene pipes for crack resistance at various temperatures. It is shown that in the weld zone a decrease in the stress intensity factor is observed up to 27% compared with the base material.

    Keywords: Polymer, polyethylene, pipe, stretching, crack resistance, low temperatures, brittle failure, crack, welding, welded joint, fusion zone

  • Analysis of theoretical and real reinforcement of the monolithic slab in different variants of seismic action

    In this article the comparative analysis of reinforcement of monolithic reinforced concrete plate under various conditions of calculation is made: without seismic actions, with design earthquake and with maximum design earthquake. It was found that taking into account the seismicity of 9 points without the use of methods of active seismic protection leads to an increase reinforcement to 28 % when taking into account the design earthquake and 81 % when calculating the maximum design earthquake. In addition, the analysis of the tool "Consumption of concrete and reinforcement" in the Lira-SAPR is made. The correction factor for the transition from theoretical to real reinforcement was obtained: it ranged from 2.4 to 3.0

    Keywords: seismic impact, Lira-SAPR, maximum design earthquake calculation, frame calculation, slab, reinforced concrete, specific consumption of reinforcement

  • On the question of assessing the frost resistance of concrete on the strength criterion

    Durability of concrete, including fine-grained, with alternating cyclic temperature effect of the external environment is normalized according to GOST 26633 mark on frost resistance, and frost resistance criterion for all concrete in accordance with GOST 10060-2012 is the ratio of ultimate strength on compression of the main and control samples not less than 0.9 with a coefficient of variation of strength in the series, while for concrete road and airfield pavements is another additional criterion is the loss of mass. In the previous edition of GOST 10060, the ratio of the compressive strength of the main and control samples not less than 0.95 was adopted as the criterion of frost resistance for all concretes. GOST 31357 normalizes the indicator "frost resistance of the contact zone" for a number of mortars or fine-grained concretes obtained from dry building mixtures. This indicator characterizes the ability of the solution or fine-grained concrete to maintain the strength of adhesion to the concrete base after a certain number of freeze-thaw cycles. For the brand for frost resistance of the contact zone from Fkz25 to Fkz100, the number of cycles is taken, after which the decrease in the adhesion strength to the base does not exceed 20% according to GOST 31356, and in this case the coefficient of variation of the clutch values measured in the series is not taken into account. Due to the limited information on the change in the in-series coefficient of variation of strength after cyclic freezing-thawing, as well as the ratio of frost resistance by the criterion of compressive strength and adhesion strength to the base, the purpose of this study was to identify patterns of change in the in-series coefficient of variation of strength and adhesion strength to the base of fine-grained concretes obtained from dry building mixtures based on various Portland cements with the content of various redispersible polymer powders from 0 to 3%. The studies were carried out on the basis of 75 freeze-thaw cycles. This paper presents the results on the change in the coefficient of variation of strength after cyclic freezing-thawing and the ratio of frost resistance coefficients

    Keywords: frost resistance of concrete, coefficient of variation of strength, coefficient of frost resistance, fine-grained concrete, dry mixes

  • The effect of redispersible powders and low modulus inclusions on the properties of fine-grained concrete after repeated freezing-thawing

    Low-modulus inclusions in the form of entrained air or ash microspheres in the composition of fine-grained concrete practically do not affect the ratio of the ultimate strength in bending and compression during hardening of concrete under normal conditions. After 75 freezing-thawing cycles, the ratio of the flexural and compressive strengths of fine-grained concrete with ash microspheres did not change, and in concretes with involved air, the influence of factors such as the type and dosage of redispersible powder and the type of cement increased sharply. Low-modulus inclusions have practically no effect on the ratio between the initial elastic modulus and the compressive strength of fine-grained concrete during hardening under normal conditions. After 75 cycles of freezing and thawing in concrete with entrained air, the influence of such factors as the type and dosage of redispersible powder and the type of cement on the ratio of the initial elastic modulus to compressive strength increases sharply. The cyclic freezing-thawing does not affect on the ratio of module and strength in concretes with an ash microsphere. Regardless of the presence of low-modulus inclusions, there is no clear relationship between adhesion to a concrete base and flexural strength of fine-grained concrete. In concretes with entrained air, the increase in adhesion to the concrete base after 75 freezing-thawing cycles, depending on the type of cement and dosage of redispersible powder, was up to 82%, and for compositions with an ash microsphere, up to 62%. Regardless of the presence of low-modulus inclusions, after 75 freeze-thaw cycles, adhesion to the base corresponds to class C-1. With an increase in the dosage of redispersible powder from 0 to 3% in compositions with low-modulus inclusions, an increase in adhesion to the base was noted up to 62%.

    Keywords: dry mortar mixes, redispersible polymer powders, low modulus inclusions, adhesion to the base, elastic modulus, tensile strength, freezing and thawing cycles

  • The method of chemical modification of epoxy compositions

    The article presents theoretical studies of the effect of various plasticizers on the mechanical properties of epoxy compositions. Based on this, the method of plasticization of the epoxy polymer ED-22 was chosen using the introduction of modified epoxy resin UP-563, which differs from the previously used modified compositions for repairing automotive vehicles in the field the simplicity of the availability of modifications in the field and as providing the widest range of changes in the properties of the epoxy composition for USAGE field. The scientific novelty lies in the justification for the creation of a new repair composition consisting of ED-22 epoxy-diane resin modified by UP-563 laproxil for the repair of hull and capacitive parts of automotive equipment in the field, which has increased vibration resistance. frost resistance and impact resistance.

    Keywords: epoxy composition, epoxy resin, restoration, automotive engineering, body part, chemical modification, oligomer, polymer

  • Dependence of frequencies of free oscillations of a thin-walled underground gas pipeline of large diameter on the depth of laying

    In this paper, the previously obtained equation of motion in displacements is used to determine the frequencies and forms of free oscillations of the underground gas pipeline. The problem of solving this equation is reduced to finding the eigenvalues of the determinant, which are the squares of the natural frequencies of the cylindrical shell. Neglecting the secondary coefficients of the determinant and equating them to zero, the formula for the square of natural frequencies of an underground rectilinear thin-walled gas pipeline exposed to the action of internal working pressure and longitudinal force is obtained, taking into account the reaction of elastic resistance of the soil. Substituting the values for the wave numbers in the longitudinal and circumferential directions into the obtained formula, expressions for determining the frequencies according to the rod and shell theory are derived.Using these expressions, the dependence of the frequencies of free oscillations of the depth of the pipeline at fixed values of the pipe wall thickness, the coefficient of elastic resistance of the soil and the length parameter of the plot, for different values of internal pressure, the ratio of longitudinal compressive forces. When analyzing the results, it was found that with increasing depth of the pipeline, the frequency of free oscillations decreases, and at a certain depth, the frequency of free oscillations becomes equal to zero, this indicates a flattening of the cross section of the pipeline. Using the dynamic stability criterion, for which the frequency of free oscillations turns to zero, an expression is obtained that allows to determine the depth of the pipeline at which the stability loss of the second kind occurs.

    Keywords: pipeline, frequency of free oscillations, depth of laying, coefficient of elastic resistance of soil, loss of stability