Within the Tresca yield criterion and its associated flow rule, the stress-strain problem in an elastic-plastic thin circular solid disk is considered under a temperature field such as the yield stress of the material depends on the temperature. In the central part of the disk the temperature is homogeneous. On the outer boundary, the disk is subjected to uniformly distributed pressure and constant temperature. The objective of the paper is to determine the service conditions which allow to obtain the temperature in the central part of the disk and its radius such as the initiation of the plastic zone starts either from the center of the disk or from its outer contour. The elastic-plastic boundary is calculated, and the plots for stresses and strains are presented. To verify the solution, the equivalent stresses for permissible plastic regimes are investigated together with the stress vector hodograph . The algorithm of similar problems is developed. The validity of the usage of the Tresca yield criterion when the yield stress of the material depends on the temperature is discussed.

Keywords: mathematical modeling, elastoplastic body, plane stress state, piecewise linear plasticity conditions, plastic flow theory, thermoelastic plasticity

The frequency divider for 32, operating in a range of frequencies 8-18 GHz is considered. The specifics of the schematic diagram is shown. The design and element base is described in short. The model is made and its experimental research is carried out. The technique and the block diagram of the experiment is described. Level of harmonics of an output signal is measured. For decrease of level of harmonics of the useful signal the low-pass filter of type SALF-580 is used. Presence of a parasitic output signal in the absence of an input signal is revelead.

Keywords: frequency divider, microcircuit, experiment, amplitude-frequency characteristic, low-pass filter

Results of realization of a cylindrical dielectric wave guide of the SHF oven of range with the entered periodic not uniformity are presented in article. Besides the question of a research of influence of phase shift on the characteristic of a dielectric wave guide, and also dependence of change of characteristics on the provision of polarization of the field is brought up.

Keywords: SHF dielecric cilcular waveguide whith bragg periodic inhomogeneities

The article examines the relevance of the study of new coatings, with the possibility of controlling their characteristics. At the beginning of the article, we review the available methods for creating frequency-selective surfaces. Next, the created controlled frequency-selective surfaces are considered. The same is said about the construction of the created surfaces. At the end of the article, an analysis is made of the results obtained on the study of controlled frequency-selective surfaces, a comparison with previously obtained results.

Keywords: control, frequency-selective surface, microwave, radio-absorbing material

The article discusses the analysis of the directivity pattern of a symmetrical vibrator from a different spectrum of a broadband signal, to improve the quality of information transmission. The calculation of the directivity pattern of a symmetrical vibrator has been carried out.

Keywords: field strenght, symmetrical vibrator, beam pattern, broadband signal

This work starts a series of the articles devoted to the analysis of the processes taking place in poorly structured and geopolitically unstable zones (regions) of the contemporary world. Considering the analysis of the specific situations as a special scientific procedure, the author looks at length at the instrumentation which is supposed to be used by a researcher of a relevant profile. The author proves the thesis of the inadmissibility of contrasting exact and non-exact methods in the investigation of geopolitical problems in the unstable and turbulent environment. Special attention is paid to revealing the possibilities of various forms of modelling which is more extensively used in the regional geopolitics. The analysis of the specific situations is interpreted by the author as a complex multi-level work consisting of two phases.

Keywords: contemporary world, geopolitically unstable zones and regions, analysis of the specific situations (ASS), situational analysis, historical descriptive methods in ASS, geographical and geopolitical mapping, methods of formalization and quantification

This work presents the second article within the series devoted to the peculiarities of the analysis of the situations in geopolitically unstable zones (regions) of the contemporary world. The author focuses on the first stage of this scientific procedure. It includes the determination of the geographical parameters of the region under investigation (or the problematic zone of the world), the study of the topography of the involved political powers and compiling their basic characteristics as well as the identification of the overall “architecture” the studied site.

Keywords: system analysis, situational analysis,“place-action” (pad), “local” states, the status and viability of the states, the geopolitical taxonomy of the region, the state’s power, the potential of the state, national interests, axis of national interests

Using simulation and finite element method calculations of stress-strain state of monolithic concrete support for underground structures with non-circular outlines made of fast-hardening concrete are carried out in the paper. Based on the obtained results, the maximum stress zones and their magnitude in the reinforced concrete support are established. The stresses are compared with circular-form supports. The factors influencing the stress state of the support are determined.

Keywords: Underground structures; soils; concrete support; voltage; the experiment plan; modeling; finite element method

High cost and shortage of cement in the construction market of the Russian Federation determines the need to find ways to save it. One of the promising directions of improving the technology of concrete, providing the opportunity for significant savings of cement is the production of concretes of new generation. Such concretes are of high quality or highly functional. Mandatory element of the technology of such concretes is the introduction in their composition of organic additives (OMD). Using the methods of the experiment planning theory in the developed compositions of organic additives depending on the fineness of the mineral component and dosage of superplasticizer. It is established that the use of the proposed organic-mineral additives will allow to save from 15 to 30% of cement without loss of concrete strength.

Keywords: saving of cement, superplasticizer, mineral component, organic additive, the strength of concrete, design of experiments

Discusses the calculation of a water tower Rozhnovskogo design, in the form of a welded sheet construction, structurally consisting of a tank of cylindrical shape with a conical bottom and a cylindrical roof and pillars. Performed creating finite element analysis model and the determination of the stresses in the tower elements with regard to the various features of the design, installation and operation of the facility. Discusses the local stability of the wall at the junction of cylindrical and conical parts. The necessity of the device the ribs in the conical part along the meridional direction and in the junction of annular ribs.

Keywords: Tower, leaf design, reservoir, resistance, voltage

"Environmental safety of rural areas" means the safety of natural and artificial ecological systems, technospheric objects and the population. On the example of Neklinovsky district of Rostov region the key role of ecological monitoring of drinking water quality in the system of environmental safety

Keywords: ecological safety of rural areas, sustainable development of rural areas

This article discusses current trends in the design field. The results of the pilot survey conducted in November 2017 the aim of the study was to identify demand for services freelance designer environmental spaces in the youth environment. Describes the main functional properties of a design project, revealed of style trends and color preferences; determined a reasonable time of the execution of the design project and the average price of design services in the field of building design.

Keywords: Terehova E.V.

The article gives judgments, focuses on the need for the development of military and town-planning sciences, based on the reality of practice, which, apart from armament, must take into account the urban and architectural components formed as a special kind of weapon of future wars.

Keywords: Urban planning, Armed forces, military science, architecture, defense infrastructure, housing

The article confirms the importance of garrison services in ensuring combat capability and combat readiness. It was stated that the service industry of any military town should become a heuristic model of building service networks for all other populated areas and their social groups.

Keywords: Garrison services, combat readiness, combat capability, Armed forces, architectural and planning organization, defense infrastructure

We consider an articulated reinforced beam from a bimodule material on an elastic base under the action of a concentrated force. Numerical investigation of the influence of the bimodule property of the beam material on the bending moment and deflection is given. The influence of the elastic bedding coefficient on the value of the maximum normal stress, the maximum bending moment and the maximum deflection is shown. Investigations were carried out for fibre-foam concrete beams, for which tensile modulus and compression moduli obtained experimentally are known. Numerical studies have shown that taking into account the bimodulity of the material, that is, taking into account the difference in elasticity modulus between tensile and modulus of elasticity for compression for concrete, leads to the need for calculation of strength both in tensile and compressive stresses.

Keywords: Reinforced beam, bimodule material, normal stress, elastic Winkler base