bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on survivability of mesh hyperboloid structures
Authors: Samokhvalov Ivan , Erofeev Vladimir 
Published: August 2020

Abstract
The object of study is a mesh hyperboloid tower, which has a base diameter of 34 meters and a height of 128 meters, constructed by an engineer V.G. Shukhov. The survivability property of the mesh hyperboloid tower was accepted as a subject of research. The aim of the work is to perform a numerical calculation of the mesh hyperboloid tower for survivability in a static setting, under conditions of failure of individual load-bearing elements of the system as a result of an accident. This calculation evaluates the survivability of the structure. The research methodology involves consideration of several options for the collapse of the bearing elements: 1. Collapse of the intermediate rings of the 1st and 2nd tiers and 16 racks of the mesh tower, excluding power transmission cables; 2. Collapse of the intermediate rings of the 1st and 2nd tiers and 16 racks of the mesh tower, taking into account the influence of the load from the power transmission cables during operation. As a result, the most dangerous destruction zones are identified, from the point of view of the survivability of the structure, the survivability coefficient of the mesh tower, as a whole is determined. As a result of the calculations, it was revealed that when the intermediate rings and 16 racks in the tower elements are removed, the efforts in the elements adjacent to the collapse zone increase by 2.6 times. The asymmetry of the load on the removed elements plays a significant role in changing the efforts. With the removal of the intermediate rings of the 1st and 2nd tiers and 16 racks, the zone of the 1st lower tier becomes the most loaded. Compression efforts in the remaining racks of this tier increase by 150%. In addition, the number of compressed-bendable elements of the tower shell increase. The results of this work can be used by designers to calculate structures’ survivability.
Thermal protective qualities of the combined material with reflective thermal insulation from aluminium foil
Authors: Umnyakova Nina 
Published: August 2020

Abstract
The article presents the results of experimental and theoretical studies of the thermal insulation qualities of foamed polyethylene with layers of reflective thermal insulation located in its thickness. Currently, the determination of the heat-protection properties of multilayer materials with reflective thermal insulation is carried out experimentally in laboratory conditions. Theoretical studies of the processes of heat transfer in the bulk of such multilayer materials and developed thermophysical model of the heat transfer process through this combined multilayer thermal insulation allowed to develop an engineering calculation method for determining the thermal resistance of multilayer polyethylene foam with reflective thermal insulation from aluminium foil, taking into account thermal conductivity and radiation. The obtained values of the thermal resistance of multilayer polyethylene of various thicknesses by calculation showed the convergence with experimental values. This indicates that reflective thermal insulation with a low emissivity of the surface, located in the thickness of the foamed polyethylene, increases its thermal performance qualities.
Basement vibration isolation efficiency investigation
Authors: Smirnov Vladimir 
Published: August 2020

Abstract
The article deals with experimental investigation of insertion loss estimation for a building elastic shielding vibration isolation system. Precision mechatronics production facility is located inside it with VC-D requirements for their foundation vibration level. A road with double tram lines lays 23 m off the exterior building’s walls producing reasonable vibration background noise. In order to reduce surface wave amplitudes elastic layer of Sylomer® polyurethane pads are glued to the underground exterior walls of the building. The vibration measurements were conducted before and after the elastic shield installation and the insertion loss was estimated using these results. Moreover, simultaneous dual channel analysis of vibration transfer through the wall structure was evaluated. Measured vibration isolation efficiency reaches 14 dB in octave band 31.5 Hz in vertical and from 9 to 15 dB in horizontal direction. For higher frequencies vibration isolation efficiency reduces due to wave effects in the isolators.
Relative brightness of facades in the L-shaped urban buildings
Authors: Zemtsov Viktor , Korkina Elena , Zemtsov Vladimir 
Published: August 2020

AbstractDay lighting of premises under conditions of compacted urban development is depended of brightness of the finishing material of the facades of buildings of the surrounding buildings. Measure of influence of opposing buildings on the light regime of the premises is determined by relative brightness coefficient of facade, which is the ratio of the brightness of the facade to the average brightness of the sky. Derivation of the formula for coefficient of relative brightness of the facade in L-shaped urban buildings is presented. The derivation of the formula is based on the some components. The first component is the light transmission rate component on the facade of the designed building, which takes into account the reflection of daylight from an area of the earth’s surface. The second component is a coefficient, which takes into account the increase in the light transmission rate component on the facade of the projected building. This is due to the exchange of reflected light fluxes between the facades of the buildings and the land surface, which is adjoined to the buildings. Relative brightness coefficient values are calculated depending on the building geometry and the reflective properties of the facade finishing material.
Structural solutions of wood-concrete floors using shear-resistant joints
Authors: Labudin B V , Popov E V , Sopilov V V , Nikitina T A , Karelsky A V , Bardin I N , Vakhlov D G 
Published: August 2020

Abstract
Currently, various composite structures made of wood, steel and concrete are used in construction. Some studies are aimed at developing the direction of wood-concrete slab-ribbed structures. Analyzing the methods of joining wood-concrete structures, it was found that the stiffness at the “edge-slab” border has a significant effect on the stress-strain state of the whole structure, and rigid joints allow using the positive properties of concrete and wood materials more rationally, taking into account structural, rheological and physical properties. To increase the shear resistance at the border of joining, a new combined joint based on the unilateral gear plate “Bulldog” and a screw nog is proposed. A numerical model has been made to calculate the joint deformation due to the action of a single shear force, which is based on the law of deformation of linearly elastic materials and the Winkler model. It describes the deformation of a nog lying on an elastically deformable base. Empirical formulae were used to take into account the nonlinearity of deformations during the long-term impact of force on the joint in conjunction with the anisotropy of wood. The dependence curves of the joint stiffness coefficient on the diameter of nog, gear plate and the restraint value of nog in the wood are constructed for dowel and combined joints. It was shown that reinforcement of the joints (up to 6-7 times) could be achieved by increasing the diameter of the nog, and combined compounds based on a gear plate allows to increase this indicator by 2…4 times. The use of screws is recommended as cross-links, the presence of concrete in the head and thread in the wood will reduce the negative effect of warping of wood during shrinkage on the operation of the proposed compounds.
Parametric oscillations of viscoelastic orthotropic plates of variable thickness
Authors: Normuminov Bakhodir , Abdikarimov Rustamkhan , Khodzhaev Dadakhan , Khafizova Zulfiya 
Published: August 2020

Abstract
Viscoelastic orthotropic rectangular plates of variable thickness are considered in the paper under the effect of periodic load. It is believed that under periodic load, the plates allow displacements commensurate with their thickness. Based on the Kirchhoff-Love hypothesis, a mathematical model of the problem of parametric oscillations of a viscoelastic orthotropic rectangular plate of variable thickness is constructed in a geometrically nonlinear statement. A method for solving the problem under consideration is proposed, based on the application of the Bubnov-Galerkin method with polynomial approximation of displacements and deflection, and on a numerical method based on the use of quadrature formulas. In calculations, the three-parameter Koltunov-Rzhanitsyn kernel is used as a weakly singular kernel. Based on the algorithm for solving the problem, a program was developed in the Delphi algorithmic language to solve the problem of parametric oscillations of viscoelastic orthotropic rectangular plates of variable thickness under the effect of an external periodic load. The effect of geometrical nonlinearity, viscoelastic properties of the material, physico-mechanical and geometrical parameters of a viscoelastic orthotropic plate on the areas of dynamic instability was investigated. The results obtained are in good agreement with the results of other authors.
Dynamic stability of viscoelastic rectangular plates with concentrated masses
Authors: Khodzhaev Dadakhan , Abdikarimov Rustamkhan , Normuminov Bakhodir 
Published: August 2020

Abstract
Thin-walled constructions such as plates and shells, with installed units, devices and assemblies, are widely used in engineering and construction. In calculations, such attached elements are considered as concentrated at points and rigidly fixed elements. The influence of concentrated masses is taken into account in the equation of motion using the Dirac delta function. Recently, more and more attention has been paid to the nonlinear and inhomogeneous properties of a structure. Dynamic stability of viscoelastic orthotropic rectangular plates with concentrated masses in a geometrically nonlinear statement is considered in the paper. Using the Bubnov-Galerkin method, based on a polynomial approximation of deflections, the problem is reduced to solving a system of ordinary nonlinear integro-differential equations. The results of the problem are obtained by the proposed numerical method based on the use of quadrature formulas. Dynamic stability of viscoelastic rectangular plates with concentrated masses under various boundary conditions was studied over a wide range of changes in physico-mechanical and geometrical parameters of the plate.
Improving the resistance of frame buildings to emergency impact through voltage regulation
Authors: Chernyh Alexander , Moskalev Mikhail 
Published: August 2020

Abstract
In recent decades, especially after the September 11, 2001 attacks, more and more attention has been started to pay to the problems of the progressive collapse of frame buildings. This problem is especially topical while constructing the buildings with an increased level of responsibility. This problem is mostly solved by duplicating of supporting structure elements which results in significant increasing the cost of building structures. However, there is the other approach: by using the tension resisting ties, strained in accident, the structure can be relieved. Under this study a numerical experiment has been performed using the Scad software to proof this theory. For the numerical experiment there was chosen a building with two bays each 30 meters long at 6 meter intervals of load-bearing structures. According to the results of numerical simulation more than 20% of the supporting structures’ material has been saved compared to the absence of ties. This approach can be taken to the construction of almost all frame buildings with an increased level of responsibility and allows saving material.
Qualification tests of adhesive systems, the assessment of the durability of glued wooden structures
Authors: Chernykh Aleksandr , Kazakevich Tatyana , Kiryutina Svetlana , Korolkov Dmitry , Nizhegorodtsev Denis 
Published: August 2020

Abstract
The question of the use of qualification tests of adhesive systems to determine their residual life is considered. The purpose of the study. Testing the hypothesis about the possibility of applying qualification tests of adhesive systems and regression equations to predict the residual life. Methods. Experimental studies of water resistance of adhesive joints, tensile strength along fibers, heat and frost resistance of adhesive joints, and resistance of adhesive joints to delamination were carried out. Results. Based on the test results, data were obtained on the water resistance of adhesive joints, the tensile strength along fibers, the heat and frost resistance of adhesive joints and the resistance of adhesive joints to delamination. The dependences of the limit on the strength of time are obtained. The residual life was calculated using the obtained equations. Discussion. Based on the studies, it was found that the qualification test data of adhesive systems can be used to determine their durability (residual life). In the future, the results of these studies can be applied for widespread implementation and for inclusion in regulatory documents.
Dynamic loading of the beam on the Pasternak base initiated by the sudden settlement of part of the base
Authors: Travush V I , Gordon V A , Kolchunov V I , Leontiev E V 
Published: August 2020

Abstract
The article presents a methodology for the analytical assessment of the dynamic loading of a beam based on a mathematical model of a transient dynamic process in a loaded structure resting on an elastic two-parameter Pasternak base, initiated by sudden settlement of a part of the base. Determine that the sudden formation of a defect leads to a decrease in the overall rigidity of the structure and a violation of the static balance of the beam-base system. The arising inertia forces cause a dynamic response, redistribution and growth of deformations and stresses. As a result, there may be a violation of the regular functioning of the structure, loss of bearing capacity and destruction. From the standpoint of structural mechanics, the problem boils down to an analysis of the manifestations of structural nonlinearity of a loaded elastic system. It is shown that the factor of sudden formation of a defect significantly increases internal forces compared with the quasistatic formation of the same defect. It is also shown that taking into account the Pasternak parameter reduces (compared with the one-parameter Winkler base) the level of dynamic bending moments during sudden partial destruction of the base.
Causes of defects in timber arches of the buildings covering and methods of strengthening
Authors: Naichuk A Ya 
Published: August 2020

Abstract
The results of the survey of covering of large-span public buildings located on the territory of the Republic of Belarus, which are in exploitation from 10 to 30 years. The bearing structures of the covering were timber glued arches with spans from 48 m to 60 m. the Main defects were both through and deep cracks that appeared in the timber of the arches during exploitation. To restore the performance of timber arches with defects in the form of cracks, methods of strengthening are proposed. The effectiveness of using glued steel rods for strengthening arches with cracks was tested experimentally. For this purpose, two prototypes of semi-arches made of glued timber for a span of 26.9 m were tested: one semi-arch of a solid cross-section bxh = 100 × 670 mm; the second semi-arch with a crack on the neutral axis, reinforced with glued steel rods. As a result of tests, the ultimate load of a semi-arch with a solid cross-section is 2.4 times greater than the calculated value; and a semi – arch with a crack through the entire length is 1.8 times greater.
Atmospheric dispersion modelling of dust emissions from the dried bottom of the Aral Sea
Authors: Ravshanov Z , Abdullaev Z , Khafizov O 
Published: August 2020

Abstract
The problem of spreading of harmful emissions from the dried part of the Aral Sea is extremely relevant for the Central Asian region, but it is also important for other countries of the near and far abroad in view of the transboundary transport of pollutants in the atmosphere. In order to solve the problem of predicting the distribution of the concentration of air pollutants, researchers are usually use mathematical tools. Modelling the processes of transport and diffusion of pollutants in the atmosphere claims to address various factors, such as weather and climate conditions, soil erosion, physic and mechanical properties of aerosol particles, etc. Thus, this study was aimed to develop a model and computational algorithm for solving the problem. The particular attention was paid to the description of wind erosion since most emissions in the Aral Sea region occur by the removal of salt-dust particles from the soil surface. There were conducted a series of computational experiments using the developed mathematical apparatus. The obtained results presented in the paper are illustrating the influence of various factors on the process of atmospheric dispersion. Comparison of the results of computational experiments with experimental data showed sufficient agreement, which confirms the adequacy of the developed mathematical model of the process of spreading of fine aerosol particles in the atmosphere.
Ground and confined underground waters and their salt content
Authors: Ravshanov N , Daliev Sh , Abdullaev Z , Khafizov O 
Published: August 2020

Abstract
A article developed a mathematical model for monitoring and predicting changes in groundwater level and salt concentration, as well as for representing the process of flooding, salinization and waterlogging in the design of hydraulic structures. A qualitative analysis of the research work on this issue is presented. Since the process is represented by a nonlinear differential equation, a numerical algorithm based on finite-difference schemes was developed to solve it. Mathematical models of the processes of geofiltration of salt migration have been improved and computational algorithms have been developed. A numerical algorithm has been developed for calculating the problem of changing the groundwater level, taking into account active porosity, flow rate in two-layer formations.
Production of wooden I-beams from angular elements for low-rise housing
Authors: Byzov V E , Melekhov V I , Toropov A S 
Published: August 2020

Abstract
Due to the deterioration of the environmental situation, an increasing number of coniferous trees are affected by butt heart rot. For a more sustainable use of resources, one needs to use round assortments with the presence of sound rot for the manufacture of sawn products. I-beams are widely used in low-rise wooden housing construction. High installation speed without the use of heavy equipment and ease of assembly increase the speed and adaptability of building construction. A method for manufacturing I-beams from corner elements obtained as a result of cutting round timber with heart rot is proposed. The elements of the angular cross section are glued together to obtain an I-beam. The strength characteristics of an I-beam glued from angular cross-sectional elements are determined. It was established that the design characteristics of I-beams obtained by the proposed technology withstand operational loads. Values of normative and shear stresses arising upon application of loads do not exceed 50% of the permissible values. The beam deflection does not exceed 80% of the permissible deflection value. The use of round timber with core rot increases wood resources for low-rise housing.
Physical essence of the “nagel effect” for main reinforcement in an inclined crack of reinforced concrete structures
Authors: Kolchunov V , Smirnov B , Naumov N 
Published: August 2020

AbstractThe physical essence of the “nagel effect” for main reinforcement in an inclined crack of reinforced concrete structures for the model of deformation of reinforced concrete structures includes formation of the first block and the second block of an inclined crack. This effect is considered is constructions under the action of vertical load, with linear displacements (normal to the axis of the beam) and rotations of the fixed end. We can find the unknownτadfrom the canonical equations for structural mechanics. When we multiply the single diagrams of bending moments caused by displacements Δ1and Δ2and displacement caused by longitudal forceNs(x) and incrementΔNs. In this case, for the “nagel effect”, we take into account the presence of several forces and displacements: the force P1 for the surface for the second block; adhesion to the surface of the reinforcementτadand a special force for the effect of discontinuity (ΔT); displacements for mutual shifts of the crack edges (Δ1); movement from the width of the crack opening (Δ2=acrc); angle of rotation for the fixed ends; variable longitudinal force in the fixed ends.
Energy efficiency of multi-apartment residential houses with individual heat supply
Authors: Navaseltsau Uladzimir , Navaseltsava Dzina , Shenogin Mikhail 
Published: August 2020

Abstract
The aim of this work is to study the functioning of heating and hot water systems of the discussed houses, to find the reasons for increased energy consumption. Four energy-efficient houses in the Brest region (Republic of Belarus) with apartment heat supply and a mechanical ventilation system with heat recovery were selected as the object of study. The research methodology of the heating and hot water supply systems of the houses consisted of the following stages: study of project documentation; thermal imaging inspection of building structures and instrumental studies of the operation of heating systems and hot water supply; questionnaire of residents to analyze the nature of their use of the studied systems; processing received data. The values of the operational specific consumption of thermal energy for heating were determined, which doubled the design values equal to 43 kW·h/m2. The main reasons for the excess of the operating specific consumption of thermal energy for heating and ventilation over the design value is the increased heating season compared to the design average for a month and the maintenance of elevated indoor air temperatures in apartments, on average, at +21°C, which leads to increased heat losses. The functioning of the hot water supply system of energy-efficient houses is generally satisfactory for the used design solution, but sometimes due to the specific appartments’ planning leads to an excessive consumption of water and causes dissatisfaction of residents with a long waiting time for hot water with required temperature. Studies have shown that currently, the existing tariff policy in the Republic of Belarus due to low tariffs for gas and thermal energy for the population does not contribute to the efficient use of energy-efficient solutions by the masses of the population, which leads to an excessive consumption of thermal energy in modern residential buildings.