Herald of Dagestan State Technical University. Technical Sciences最新文献

{"title":"Study of work of PVC membranes for engineering waterproofing under increased seismic conditions","authors":"V. Shalimov, A. V. Tsybenko, I. Goglev, S. Loginova","doi":"10.21822/2073-6185-2023-50-1-229-237","DOIUrl":"https://doi.org/10.21822/2073-6185-2023-50-1-229-237","url":null,"abstract":"Objective. At present, increased requirements are imposed on waterproofing materials used in seismic hazard zones. The aim of the study is to assess the possibility of using LOGICBASE™ polymer membranes in regions of increased seismic activity in the Russian Federation.Method. The mechanism of operation of polymeric membranes in foundation structures under conditions of constant displacement and friction is considered. Experiments were carried out to determine the coefficient of friction according to the method of state standards on a tensile testing machine MIRK-1000K. Samples of a round shape made of polymeric membranes were studied on a special multiaxial stretching device in accordance with the requirements of state standards.Result. Multiaxial tensile testing of LOGICBASE™ V-SL polymeric membranes revealed that the maximum tensile strength of the samples was 6948.22 kPa (~ 6.95 MPa), and the elongation of the samples at break was 113.89%. The coefficient of friction in the system \"polymer waterproofing material - concrete structure\" was determined under conditions of increased seismic activity according to the MSK-64 scale.Conclusion. According to the studies, it was concluded that PVC membranes for engineering waterproofing can be used in construction areas with seismicity up to 9 points inclusive on the MSK-64 scale.","PeriodicalId":202454,"journal":{"name":"Herald of Dagestan State Technical University. Technical Sciences","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132072253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Virtual test bench for computer-aided design of drum dryers based on kinetic laws of the drying process","authors":"V. Tkach, A. Shevtsov","doi":"10.21822/2073-6185-2023-50-1-152-160","DOIUrl":"https://doi.org/10.21822/2073-6185-2023-50-1-152-160","url":null,"abstract":"The aim of the study is to create a virtual test bench, consisting of optimal design parameters that provide the maximum approximation of the real drying process to the experimental data.Method. Methods of modeling, formalized description, optimal design and management of technological processes and productions are applied. Result. A virtual test bench has been developed that allows real-time determination of the design parameters of drum-type dryers depending on the kinetic patterns of the drying process of various grain crops. As an object of study, the design of a two-section drum dryer was used, each section of which is equipped with a profile channel nozzle that provides a transverse supply of the drying agent through the pouring movable layer of the dispersed product to be dried. An algorithm for calculating the drying process is presented, which makes it possible to determine the fields of temperature and moisture content of grain in a wide range of regime parameters. With the use of CAD, a computer model of this installation was made with the possibility of autonomous rotation and movement of the drums relative to each other. A diagram of the synchronized operation of the moving elements of the installation under conditions of operational reconfiguration of its design in accordance with changes in the kinetic curves has been drawn up.Conclusion. The presented virtual test stand adequately and with high accuracy allows simulating the process of drying materials in a drum dryer; allows you to test the operation of a drum dryer at the development stage, conduct experiments with the highest possible accuracy, select the optimal drying modes for various materials with minimal energy consumption.","PeriodicalId":202454,"journal":{"name":"Herald of Dagestan State Technical University. Technical Sciences","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126415126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of liquid fuel combustion processes in an electrostatic fieldе","authors":"R. Mukanov, Y. Alyautdinova, S. Strelkov","doi":"10.21822/2073-6185-2023-50-1-207-214","DOIUrl":"https://doi.org/10.21822/2073-6185-2023-50-1-207-214","url":null,"abstract":"Objective. The article presents the results of experimental studies on the effect of a high-potential electrostatic field on the combustion of liquid fuel. Method. Experimental studies were carried out on the developed laboratory installation, which makes it possible to ensure the combustion of liquid fuel in a high-potential electrostatic field with the possibility of changing the polarity. The change in the polarity of the applied voltage to the electrode system of the experimental setup led to an increase in the fuel burning rate in the first case, and to its attenuation in the second.Result. In this paper, studies have been carried out proving the effect of an electrostatic field on the burning rate and reducing the content of harmful components (soot and carbon monoxide) in fuel combustion purges. Based on the values of the fuel burning rate obtained as a result of the experiments, graphic dependences were constructed on the applied voltage, on which the areas of linear and non-linear changes in the combustion parameters were identified.Conclusion. The results of the research carried out can be used to create new highly efficient burners for liquid fuel boilers. The effect of reducing the burning rate can be used to create fire safety devices that block the spread of flame during a fire.","PeriodicalId":202454,"journal":{"name":"Herald of Dagestan State Technical University. Technical Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126954062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On models of ground vibrations in strong earthquakes","authors":"H. R. Zainulabidova, U. D. Toturbieva, A. M. Jamaludinov","doi":"10.21822/2073-6185-2023-50-1-167-173","DOIUrl":"https://doi.org/10.21822/2073-6185-2023-50-1-167-173","url":null,"abstract":"Objective. The purpose of these studies is to determine, on the basis of the developed models describing seismic impacts, the most acceptable for acceptance from the point of view of the accuracy of the description of the seismic oscillation both in the shape of the envelope and in duration and frequency characteristics.Method. The use of empirical models in describing soil fluctuations as a random process has been considered in a number of papers. This paper presents the main simplifying assumptions used in this approach. The validity of empirical models and some difficulties encountered in modeling the oscillation process are investigated.Result. A methodology for assessing the reliability of the proposed impact models is proposed. The proposed method takes into account the soil - geological characteristics, as well as spectral data of instrumental recordings of known earthquakes.Conclusion. The seismic impact model, as well as the approximating modeling function, should be determined by the degree of responsibility of the building.","PeriodicalId":202454,"journal":{"name":"Herald of Dagestan State Technical University. Technical Sciences","volume":"18 24","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113979461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Construction and technical properties of vermiculite concrete and fibro vermiculite concrete with volcanic pumice under the influence of elevated temperatures","authors":"T. Khezhev, G. N. Khadzhishalapov, A. Zhurtov, F. Shogenova, A. V. Kalazhokov","doi":"10.21822/2073-6185-2023-50-1-215-228","DOIUrl":"https://doi.org/10.21822/2073-6185-2023-50-1-215-228","url":null,"abstract":"Objective. Development of compositions of vermiculite concrete and fibro vermiculite concrete with volcanic pumice. Investigation of the construction and technical properties of the developed compositions of vermiculite concrete and fibrovermiculite concrete with volcanic pumice under the influence of elevated temperatures.Method. Methods of increasing the fire resistance of reinforced concrete structures are considered. The research is aimed at the development of vermiculite concrete and fibro vermiculite concrete with volcanic pumice for fire protection of building structures and the manufacture of heat-resistant products and structures. To reduce the cost of vermiculite concrete, its partial replacement with volcanic pumice is proposed. For the study of vermiculite concrete with volcanic pumice reinforced with basalt fiber, a rotatable plan of the second order of the regular hexagon type was used.Result. Replacing a part of an expensive aggregate (expanded vermiculite) with pumice leads to a slight increase in the average density of the composite, while the bending and compressive strength increases. In addition, the heat-resistant properties of vermiculite concrete with pumice are increased. This is due to the fact that volcanic pumice, being a hydraulically active additive, is able to react hydration with cement components, eliminating the harmful effect of secondary hydration of free calcium oxide. The influence of the heating temperature on the change in the construction and technical properties of vermiculite concrete and fibrovermiculic concrete, including with the addition of pumice, has been studied. It was found that dispersed reinforcement with basalt fibers reduces shrinkage deformations, when heated to t = 800, the shrinkage decreases from 0.7 to 0.5% compared to the original concrete matrix.Conclusion. The dependence \"compressive strength = f (average concrete density)\" significantly depends on the presence and ratio of pumice in the composition of vermiculite concrete, while an increase in the holding temperature to 600 oC or 800 oC leads to a decrease in the compressive strength from 15 to 25%, and the main decrease occurs when heated to 600 oC, further the increase in temperature has a negligible effect. The dependence of the bending strength on the compressive strength is generally maintained regardless of the heating temperature, and the heating of concrete does not reduce the relative bending strength, i.e. the ratio of bending strength / compressive strength is not reduced. Dispersed fiber reinforcement increases the relative bending strength by about 70% regardless of the heating temperature.","PeriodicalId":202454,"journal":{"name":"Herald of Dagestan State Technical University. Technical Sciences","volume":"9 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116850134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New types of membrane-rod and membrane-pneumatic structures and improved methods for their calculation","authors":"A. Kim, S. V. Polnikov, M. F. Amoyan","doi":"10.21822/2073-6185-2023-50-1-185-193","DOIUrl":"https://doi.org/10.21822/2073-6185-2023-50-1-185-193","url":null,"abstract":"Objective. The purpose of this study was to create new pre-fabricated membrane-rod structures and non-linear methods for their calculation.Method. A stepwise method with an iterative numerical Euler-Cauchy procedure of the third order of accuracy was applied with the use of the finite element method at the step.Result. A technique for static calculation of membrane-rod structures has been developed, taking into account nonlinear factors. A calculation algorithm has been compiled and a program for calculating such structures has been written according to it. For this program, a certificate was obtained on the computer No. 2017613415 \"Program for calculating membrane-pneumatic structures, taking into account non-linear factors by the iterative method of incrementing parameters.\"Conclusion. It is recommended to use a one-step calculation of membrane-rod systems with five iterations per step or a multi-step calculation with five steps with one iteration per step. Mixed options are also effective.","PeriodicalId":202454,"journal":{"name":"Herald of Dagestan State Technical University. Technical Sciences","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132238714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of hidden defects of thermal protection of buildings and determination of some thermal properties of structural building materials by Non-destructive Thermal Imaging method","authors":"D. Karpov, M. V. Pavlov, A. G. Gudkov","doi":"10.21822/2073-6185-2023-50-1-174-184","DOIUrl":"https://doi.org/10.21822/2073-6185-2023-50-1-174-184","url":null,"abstract":"Objective. The purpose of the work is the practical approbation of a nondestructive thermal imaging method to identify hidden (invisible) defects and qualitative analysis of the thermal protection of a complex of construction objects in the city of Vologda, as well as the study of some physical (thermophysical) indicators (coefficients of thermal conductivity, thermal resistance (thermal insulation) and heat transfer) of structural building material in the form of silicate brick.Method. The fundamental laws of the theory of heat transfer, thermal nondestructive testing, infrared and technical diagnostics, the current domestic regulatory and technical and regulatory documentation, field experiments on real objects and laboratory samples.Result. The results of the practical determination of hidden defects in the thermal shells of the complex of civil and industrial buildings functioning in the urban environment, thermophysical properties (coefficients of thermal conductivity, thermal resistance (thermal insulation), heat transfer) of modern building materials by methods of thermal non-destructive testing are presented. The locations of identified invisible defects of thermal protection of the surveyed construction objects are determined and recommendations for their elimination are proposed. The obtained values of thermophysical characteristics for the studied structural building material are consistent with the data of current regulatory documents.Conclusion. The features of the nondestructive method of infrared thermography in determining the hidden defects of the heatshielding shells of operated buildings of various functional purposes and the complex of thermophysical parameters of modern structural building materials are shown. The demand for thermal imaging during energy and technical surveys of construction objects, their individual structural elements, life support engineering systems, as well as studies on the refinement, quantification and prediction of various thermal properties of building materials and products has been experimentally confirmed.","PeriodicalId":202454,"journal":{"name":"Herald of Dagestan State Technical University. Technical Sciences","volume":"363 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115898148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Filled bituminous compositions in the construction industry","authors":"O. N. Kindeev, M. Vysotskaya, A. Kurlykina","doi":"10.21822/2073-6185-2023-50-1-194-206","DOIUrl":"https://doi.org/10.21822/2073-6185-2023-50-1-194-206","url":null,"abstract":"Objective. The properties of road bitumen, when interacting with the components of building compositions, are always transformed relative to their original properties. Therefore, when working with materials based on filled bitumen compositions, regardless of their field of application, the main task is to monitor the dynamics of changes in characteristics and control in the required direction, as well as maintaining properties such as viscosity, flexibility and fluidity. The purpose of the work is to study the effect of modifying additives of various bases (fillers, plasticizers and waxes) on the properties of a bituminous binder and to evaluate the effectiveness of their contribution to the formation of filled bitumen compositions for the construction industry.Method. The methodological basis of the work is the principle of bitumen structure formation. Experimental studies were carried out using standard and special methods.Result. The results obtained showed that fiberglass fiber proved to be the best filler in the bitumen composition. In the study of plasticizers, it was revealed that the most pronounced positive plasticizing effect is observed from the use of an extract of selective oil purification, which allows you to control the flexibility of the system in a wide range. It has been established that the plasticizer polyalkylbenzene effectively regulates the properties of the composition at negative temperatures, slightly affecting the heat resistance. The results of the wax study show that Titan synthetic wax and Viscobit polyethylene wax are evenly distributed in the volume of the bituminous binder and provide stabilization of the system properties.Conclusion. In the process of performing the study, as well as analyzing the results obtained, 3 groups of bituminous matrix filler additives were studied. It has been established that the directed regulation of the properties of bitumen systems is possible due to the rational choice of the type of additive-filler. Thus, using complex fillings of the bitumen matrix when designing bitumen compositions with the possibility of regulating and normalizing their properties (optimization indicators), it is possible to obtain economic and operational effects.","PeriodicalId":202454,"journal":{"name":"Herald of Dagestan State Technical University. Technical Sciences","volume":"416 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131964752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calculation of the load-bearing capacity of the bent plates taking into account the diagrams of concrete deformation","authors":"A. Dzhankulaev, O. M. Shogenov, Z. R. Likhov, A. M. Kaziyev, I. A. Blyanikhov","doi":"10.21822/2073-6185-2023-50-1-161-166","DOIUrl":"https://doi.org/10.21822/2073-6185-2023-50-1-161-166","url":null,"abstract":"Objective. The influence of the nature of the descending branch of concrete compression and stretching diagrams on the ultimate load-bearing capacity of bent cross-section reinforced concrete structures under various loading conditions close to destruction according to the nonlinear finite element model is investigated.Method. The solution is performed by the finite element method in a physically nonlinear formulation using N.I.Karpenko's deformation theory. Deformation diagrams are used with different steepness of the descending branch. Calculations are performed by a step-by-step iterative method of successive loads on a layered model.Result. The results of numerical calculation of slab reinforced concrete elements under various conditions of physical nonlinearity of concrete are presented.Conclusion. The insignificant influence of the steepness of the descending branch on the load-bearing capacity of plate bendable structures has been found and the use of simplified diagram dependencies is fully justified for numerical calculations using a nonlinear model.","PeriodicalId":202454,"journal":{"name":"Herald of Dagestan State Technical University. Technical Sciences","volume":"07 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127169297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variant regression modeling of electricity production in the Russian Federation","authors":"S. Noskov, E. Popov, S. P. Seredkin, V. V. Tirskikh, V. Toropov","doi":"10.21822/2073-6185-2023-50-1-123-129","DOIUrl":"https://doi.org/10.21822/2073-6185-2023-50-1-123-129","url":null,"abstract":"Objective. The aim of the study is to build a linear regression model of electricity generation in the Russian Federation depending on resource indicators, which include: the volume of coal and gas production, the production of fuel oil. Statistical data for 2005 - 2020 were used as the information base of the study.Method. Estimation of unknown parameters of the linear model is carried out using three methods - least squares, modules and anti-robust estimation. They behave differently with respect to outliers in the data. The second of them does not react to outliers at all, completely ignoring them, and the third, on the contrary, strongly gravitates towards them, therefore, these methods are a kind of antagonists in relation to each other.Result. Three alternative models of a linear regression model of electricity production with high accuracy are obtained. The value of the parametric stability index of the data sample, based on the properties of the parameter estimation methods, is calculated. Observations are identified that correspond to the maximum and minimum extent to the linear model on the analyzed sample. The values of the contributions of the factors to the right parts of the models are calculated.Conclusion. Three versions of the model built by different methods can be successfully used to solve problems related to forecasting the production of electricity in the country. At the same time, the variant constructed by the least squares method is a kind of compromise.","PeriodicalId":202454,"journal":{"name":"Herald of Dagestan State Technical University. Technical Sciences","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134255943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}