The article describes the simulation in the Simulink environment of the operation of a stepper motor used as an electric drive of the scanning mechanism for the Earth orientation device. The purpose of the study is to determine the minimum power consumption in each range of values for inductance and resistance. If the model is found to be inoperable above certain values of the specified parameters, the measurement range narrows to an area where there is enough energy to properly work out a given angle. The simulation is based on the parameters of NEMA17 engines, in particular, NEMA 17HS3410. Voltage control in the system is carried out by means of a PI controller, the influence of the regulator on the energy consumption of the system is shown. The regularities of the formation of angular velocity of various amplitudes when working out a turn in open and closed control systems are noted. The range of electrical parameters at which the engine operates with almost the same power consumption is determined. The lowest power values at which the engine is operable are found. The results of the work are visualized in the form of three-dimensional surfaces, recommendations for the continuation of research are developed.

Keywords: stepper motor, simulation, Earth orientation device, power consumption

The development of technical devices in almost all industries is aimed at creating universal devices that allow performing several operations. The forest industry is no exception. The creation of a taxation tool that provides the ability to perform several measuring operations, which is the goal of the work, will increase the efficiency of the taxator while reducing the physical load on him due to the need to have fewer measuring instruments with him. All this indicates the relevance of this work. To achieve this goal, a number of tasks were solved in the course of the work, the main of which were: analysis of known designs of taxation instruments, synthesis of new technical solutions for their unification, patenting of a new technical solution. The use of system analysis made it possible to achieve the set goal, to propose a new patentable solution for a taxation device that combines the functions of an altimeter and a full gauge. The approach described in the paper to the creation of new designs of universal taxation devices can be used in teaching engineering creativity to students.

Keywords: full gauge, altimeter, taxation, forestry

Refrigerating machines are designed to cover peak heat generation in public buildings. At the same time, peak loads are often short-term and most of the time the refrigerating machines operate at 40-60% of their maximum capacity. The article deals with the issues of uneven cold consumption on the example of a sports complex located in Volgograd. When designing the air conditioning system of the games hall, a cooling system with the use of "chiller-fan coils"is used. An effective solution to reduce costs is to include a cold storage battery in the cooling station circuit. The use of a cold storage battery allows you to reduce operating costs.

Keywords: cooling system, air conditioning system, refrigeration machine, cold storage, energy consumption, peak loads, variable energy consumption

The paper presents the results of a study aimed at selecting a safe depth of an underground collector. In the scientific and normative literature there are no specific recommendations for the depth of tunneling through the existing highways. There are only recommendations for tunneling through railway embankments. Purpose of this study: scientifically substantiated recommendations for the use of reinforced concrete pipes as collector cases. The decision of problems for achievement of the objective will be carried out by means of numerical experiment - a method of finite elements.

Keywords: reinforced concrete case, underground collector, safe depth, mathematical modeling, case structures, highway, closed method of work, trenchless laying, finite element method, subsidence trough

The issues of optimization of ribbed reinforced concrete slabs with prestressing of reinforcement, taking into account geometric, strength and cost indicators, are considered. The study was car-ried out on the basis of an analysis of the sales market for building materials, the basics of rein-forced concrete resistance and the provisions of regulatory documents, design activities in the Russian Federation, as well as the works of domestic and foreign scientists. The research method is structural-analytical analysis taking into account the relationships of the factors under study. Analytical and graphic materials are presented, revealing the regularities between the geometric dimensions and the cost of components. The proposed method for determining the efficiency of a structure, taking into account the cost indicators of materials, indicates the feasibility of its ap-plication in design practice. Recommendations for design are given to ensure that structures of the minimum cost are obtained and that meet the requirements of strength and durability.

Keywords: reinforced concrete, strength, structure, reinforcement, diameter, price, cost, efficiency, dimen-sions, analysis, element

The article proposes a method for assessing the risk of a possible stay of an automated special-purpose information system in a critical state, based on the synthesis of two heterogeneous mathematical models, one of which allows taking into account the intensity of DDOS attacks and the intensity of application processing, based on Markov processes, and the second is one of the forms of a formal description of protection systems, with complete overlap, in which the interaction of the "threat area", "protected area" is considered – areas of resources of an automated information system for special purposes, and "protection systems" – security mechanisms of an automated information system. The developed method makes it possible to simulate the information security tools included in the automated information system for special purposes, under the influence of DDOS attacks, taking into account both the empirical values obtained as a result of measurements or modeling, and the theoretical base of parameters specified by input data. In the synthesis of the two models, the lack of uncertainty of some of the input parameters, taking into account the values based on expert estimates, was eliminated.

Keywords: automated information system, security assessment, queuing system, risk

This article discusses the importance of timely defect detecting of automated electronic car control systems for prevention of serious failures. Also the first stage of mathematic modeling mechanism is presented, it includes construction models of the dependence of the number of failures by time with various methods of diagnosting the technical condition of the car.

Keywords: diagnosting, modeling, technical service of the car, failure, automated system, electronic control unit, engine

The use of metal structures as load-bearing elements of building frames is incredibly extensive. They are used in all areas, from the construction of bridges to the construction of airports and other equally important facilities. Based on this, it is necessary to design such structures extremely accurately, take into account all possible effects on the elements of the building and lay the necessary safety margins. In turn, fire, as one of the extraordinary loads, must be investigated in all its aspects. From the study of the development of a fire, to the structural analysis of elements exposed to fire. This article is devoted to determining the fire resistance of steel beams by two approaches - analytical and numerical, as well as comparing the results. After testing the beam with two methods, it was concluded that the maximum value of the deflection rate in the analysis is 32.6 mm/min, which exceeds the limit value. Since only one limit condition is exceeded, the beam is considered to meet the R30 fire resistance requirement. To increase the fire resistance of the structure, it is necessary to apply various methods of protecting the beam section.

Keywords: metal structures, load-bearing element, extreme load, structural analysis, fire impact, fire resistance

In this article, the object of study is a research drying chamber of a convective type, in the design of which a condensing heat exchanger based on a vapor-compression heat pump is introduced. The drying process of lumber refers to energy-intensive technologies, since the share of drying in the cost of finished materials reaches 50% [1]. In the presented experimental study, comparative results of two operating modes of the experimental installation are presented: standard (soft mode) and recirculation mode with a condensate dryer. The obtained experimental drying curves show that the cost of electrical energy, taking into account the option with a condensing heat exchanger, decreased by 7.75% compared to the standard.

Keywords: drying modes, drying, heat pump unit, heat recovery unit, material balance, heat balance, moisture content, heat consumption, experimental setup

The article considers variants of arrangement of various reactive power compensation devices, the choice of location of which took into account both modes of operation of power grids and voltage levels in the nodes. Mathematical modeling made it possible to form an optimal calculation algorithm based on a multi-criteria approach, taking into account the possible voltage increase at the corresponding substations. However, this approach is accompanied by some increase in active power losses, so the final conclusions should be based on expert procedures.

Keywords: reactive power compensation, mathematical modeling, installation site, power losses, multi-criteria approach, calculation algorithm, power system, substation, compensating devices

The article is devoted to the use of artificial intelligence tools to solve technical problems in the construction industry. It is noted that the use of neural networks will allow taking into account the behavior of materials in various experimental conditions. The authors present a comparative analysis of approaches to neural network training, in particular, the structures of multilayer and LSTM networks are considered. It is established that LSTM networks are more effective in solving problems of identification properties of materials.

Keywords: neural network, non-destructive testing, identification task, multilayer network, LSTM network, impact indentation, indentation, strength properties of materials, neural network technologies, statistical distribution

This article analyzes the calculated fire curve in accordance with the ignition heat source in the compartment. To predict the calculated fire curve, the exponential equation proposed in the previous study was compared with the heat release rate measured in a fire experiment. The lag index, which is the main factor used to predict the time it will take to reach the maximum heat release rate, has decreased in proportion to the ignition heat source.

Keywords: fire calculation curve, pipe insulation, ignition heat source, deceleration index, heat release rate

In this article, we investigate the effectiveness of using multiple pipes for heat dissipation. The study assumes laminar flow under steady-state conditions. Various mixtures are numerically investigated at different flow rates. Various nanofluids flowing through multiple parallel pipes have been numerically investigated to study the effects of temperature rise. Thanks to the benefits they bring to the cooling process, nanofluids have opened up a new way to improve the performance of thermal systems. A typical nanofluid consists of a base fluid, which is usually water, and nanoparticles.

Keywords: heat exchanger, flow tube, nanofluid, bottom heating, coefficient of friction, pressure drop

The article describes the well-known design of a tape-shell foundation. Based on the analysis of the known design, a number of factors affecting the limitation of the scope of the tape-shell foundation are derived. In order to ensure the controlled inclusion of the reinforced concrete shell of the foundation in the work, the author of the article proposed the use of a damping gasket under the tape support contours. A gasket made of an easily compressible slab material - polystyrene foam - is compressed under the influence of the load from the walls and columns of the basement of the building, the reinforcement of the shell is stretched and involves the soil of the subshell part of the foundation. At the same time, the strength characteristics of the band-shell foundation increase, the sediment decreases. The author of the article conducted numerical studies to determine the required thickness of the gasket. It is proved that the use of a damping gasket is relevant for soils with a deformation modulus of less than 15 MPa, above this value, the use of a gasket is impractical.

Keywords: tape-shell foundation, reinforced concrete shell, tape support contour, ground whole, auxiliary method of inclusion in the shell, damping gasket, thickness of the gasket

The development of a methodology for the formation of an estimate of a construction object on the basis of its information model is considered, taking into account the state of development of software systems for BIM modeling and the peculiarities of regulatory regulation of the construction of construction projects in Russia. The factors that limit the possibility of drawing up estimate documentation for the information model have been identified. Taking into account the identified limitations, a set of operations necessary for the formation of an estimate for a construction object based on its information model is presented.

Keywords: BIM, 5D BIM-model, estimate documentation, civil and industrial construction