bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Study on Low-load Sliding Pressure Operation of Supercritical Unit
Authors: zheng Wei , Shang Panfeng , Guo Junshan , Han Yue , Zhu Lingkai , Lao Jinxu , Li Li , Ding Junqi , Ma Yihe
Published: December 2019

This work reports the variation of the heat rate (HRT) and the efficiency of the high-pressure cylinder by the test of the operation mode of different control valves of the first home-made supercritical 660MW unit. The heat consumption rate and high pressure cylinder efficiency of sequential valve operation are better than that of single valve operation, especially heat consumption rate and high pressure cylinder efficiency are quite different under low-load condition of 400MW and 500MW. Above 600MW, the economic indexes of sequential valve operation and single-valve operation with three-valve are similar, of which the heat rate and the efficiency of high-pressure cylinder are better than that of single-valve operation with four-valve. When the unit adopts the sliding pressure operation mode at the load ranging from 360MW to 550 MW, the optimal sliding pressure operating curve is different from the designed curve. According to the analysis of the experimental sliding pressure operating curve and the sliding pressure operation characteristics of the unit, the higher main steam pressure can be used to increase the throttling of the governing valve when the operating conditions close to the sliding pressure curve, which can quickly increase the load and enhance the variable load response ability and peak regulation capacity of the unit.
Sliding Mode Variable Structure Control for Three-Phase Three-Wire Active Power Filter
Authors: Chen Cong
Published: December 2019

Based on the established three-phase three-wire active power filter model, a sliding mode variable structure control method is designed. Since the active power filter (APF) is switched by the switching function continuously, a suitable sliding surface is an effective method for improving the current tracking performance. Although the ordinary hysteresis comparison method has the characteristics of fast dynamic response, good robustness and strong adaptability to loads, the chattering phenomenon is serious. In this paper, a new sliding mode variable structure control is constructed by the design of sliding surface. The simulation proved that the designed sliding mode variable structure control method has less chattering and current tracking error than hysteresis comparison, the current contains fewer harmonics after processing. The effect of overall harmonic compensation is better than the ordinary hysteresis comparison method.
Research on Interdisciplinary Characteristics: A Case Study in the Field of Artificial Intelligence
Authors: Li Shuang , Wang Yuefen
Published: December 2019

In order to show the interdisciplinary laws of the subject fields and analyze the interdisciplinary structure of the field and the contents of knowledge research, a clear-structured framework of interdisciplinary feature recognition is constructed. Taking the field of artificial intelligence as an example, this paper analyzes it from the aspects of disciplinary diversity and disciplinary coherence. Disciplinary diversity is characterized by the distribution of disciplines, Shannon entropy and Rao-Stirling index. Disciplinary coherence is based on network analysis, which mainly includes discipline citation network and core, important and marginal discipline-keyword cooccurrence network at a finer granularity level. These two levels more comprehensively show the distribution and flow of discipline knowledge in this field. Through empirical research, it is found that the field of artificial intelligence involves a variety of disciplines, and its interdisciplinary situation evolves over time, forming clusters of disciplines with tight knowledge flow. In addition, the cross-topic domains of disciplinary research are also different. The results show that the framework system has certain reliability and can provide reference for related research.
Research and Implementation of Cache Optimized Query Privacy Protection for Spatio-Temporal Data Based on PGSRQ-PIR
Authors: Qian Lin , Yu Jun , Zhu Guangxin , Xu Mingjie , Pang Hengmao , Mei Feng , Lu Wenda , Wang Lin , Chen Haiyang , Mei Zhu
Published: December 2019

In view of the high redundancy of the nearest node of the Spark based user privacy protection query algorithm CRIP-V, the caching optimization algorithm PCPIR-V-CA is proposed. PCPIR-V has two parallel strategies, row strategy and bit strategy. The bit strategy divides the row into smaller pieces and improves the efficiency while the grid division is to small. The cache optimized algorithm of PCPIR-V first clusters the CPIR data transforms the data into tuples and caches them in each cluster. Finally it calulates the result based on the cached tuples and data. It has about 20 percents improvement than PGSRQ-PIR.
Research on Analytical Monitoring System for Single-Phase Electrical Appliances
Authors: Xue Miyue , Mao Limin , Jiang Feng
Published: December 2019

In view of the limitations of the current domestic power monitoring system, in this paper an intelligent single-phase electrical appliances analysis and monitoring system have been designed.The system takes STM32 as the control core, and the electric energy metering circuit is used to collect signals. The learning and recognition functions of electrical appliances are designed.The whole single-phase electrical appliances analysis and monitoring system can be used to monitor the operation of one or more electrical appliances in the circuit and display specific electrical parameters.The system uses a special measurement chip RN8208G, and the current precision can reach 1 mA. It is reliable, suitable for long-term operation and not easy to make mistakes.In this paper, the design of a specific electrical monitoring system is novel and has broad prospects for development.
A Multi-Level Cache Management Approach of Scientific and Technical Information Data for Electric Power
Authors: Ma Yan , Zou Lida , Qi Dali , Chen Yufeng
Published: December 2019

Scientific and technical information database for electric power becomes indispensable with the development of big data and think tank in electric industry. Querying information database is time-consuming and cache management is an efficient solution. In the paper we focus on a multi-level cache management in order to improve search speed of sci-tech information. The proposed computation method of cached data value considers visiting volume, data size and user experience, which is accurate for choosing key words and caching device. Our caching management framework consists of four modules, and the used machine learning method could effectively predict the number of visits next period for key words. The experiments demonstrate that our proposed MLCM approach performs better in prediction accuracy rate, query time and user experience than traditional statistic, LRU, LFU algorithms.
Research and Implementation of Machine Learning Classifier Based on KNN
Authors: Wang Lishan
Published: December 2019

Machine learning classifier is an important part of pattern recognition system; it is also an important research field of machine learning. The main research object of this paper is K data mining (KNN, K Nearest Neighbor) classification method, using KNN to classify the data, and compare the classification results. The research work of this paper mainly discusses the implementation of KNN-based machine learning classifier, mainly focusing on the theoretical analysis of K-data mining, algorithm implementation, and implementing KNN-based machine learning classifier.
Analysis of the Application of Electronic Technology in Engineering Area
Authors: Li Yin
Published: December 2019

As a relatively new production technology in engineering technology, electronic technology can optimize and improve the complicated and tedious production process in the past, and then achieve the goal of reducing manpower and material resources and improving productivity. For this reason, this paper will discuss the application and analysis of wireless remote monitoring system and automobile machinery production, and elaborate the design and analysis of the system in the application analysis of wireless remote monitoring field, and enumerate the relevant theoretical basis. But the automobile production machinery aspect mainly focuses on the remote control system design, through the actual content carries on the research to the electronic technology application in the engineering domain.
Finite Element Analysis and Modeling of Three-Phase Induction Motor
Authors: Ding Zhilin , Bu Wenping , Cai Xing , Wu Xiaojiang , Liu Shuhua
Published: December 2019

As mentioned in this paper that three-dimensional and two-dimensional model of the motor is established and three-dimensional structure of the motor is proposed. The finite element structure of the two-dimensional motor is analyzed by using the two-dimensional finite element analysis method combined with a motor example. The finite element parameters of the motor are designed, and the state parameters of the motor involving flux diagram, magnetic line diagram, magnetic density vector diagram and magnetic density cloud diagram are obtained.
Construction of Safety Protection System for Power Industrial Control System and Enhancement Design of Communication Protocol
Authors: Wang Xiaoqiang , Zhao Rui , Yu Xuehai , Zhang Jinye
Published: December 2019

The safe and stable operation of the power system has always been a common problem related to social stability and economic development in the world. To adapt to the development of “Internet +" and energy Internet, to ensure the information security of the power industrial control side, the power industrial control system Information security raises higher requirements. First, the ICS communication model is abstracted, the security risks and threats faced by ICS are sorted out, the most urgent and critical security requirements are clarified, and then a communication enhancement scheme is designed without affecting functions, efficiency, and rapid deployment. This includes one-way authentication and integrity checking of critical communication messages, combined with a timestamp mechanism and registration mechanism. Finally, through the security analysis of the enhanced scheme, it proves that it can resist common attacks such as camouflage, tampering and replay.
Dynamic Analysis of the Flapping Mechanism of Flapping Wing Aircraft
Authors: He Wei , Zhang Ruikun , Sun Lei , Chen Xu , Luo Xiao
Published: December 2019

In order to improve the design level of bionic flapping-wing aircraft, it is necessary to find out the influence of load undulating moment on the motor under the action of air undulating moment. This paper takes flapping-wing aircraft with a crank and rocker mechanism as a flapping mechanism as an example. Firstly, the kinematics model of the flapping mechanism is established, and the relative motion parameters are obtained. Secondly, the dynamic model of flapping-wing aircraft is deduced by using Lagrange dynamic equation. Then, based on the strip method, the aerodynamic moment of air to flapping aircraft is calculated, and the obtained aerodynamic moment is substituted into the dynamic model of the system, to calculate the torque fluctuation on the crank during the flapping flight of flapping aircraft by MATLAB. Finally, in order to verify the correctness of the model, ADAMS software is used to simulate the system, and the simulation results are consistent with the calculated results of the model, thus proving the correctness of the model.
High-accurate Resistance Measurement Method for Sensor Circuit
Authors: Chen Xiaoming , Li Tianze , Zhao Danna , Zhu Huichao
Published: December 2019

An accurate resistance measuring circuit which is used complementary measurement and input compensation to make radiometric method as ideal as possible and reduce the influence that OAs’ stray terms results based on radiometric method and dual-slope ADC circuit is proposed to solve the problem that we can’t balance the precision and detection range of resistance measurement. The accuracy of method is almost related to the reference resistor. It can be calculated that the resistances near the reference resistance measurement error is less than 0.02% after using the complementary measurement under the high-precision OAs, and the measurement error is an order of magnitude smaller after using the input compensation. It is shows that the measurement error could be less than 1% with non-precision OAs. This circuit can be widely applied to sensor circuit.
Design and Simulation of Two Phase Doubly Salient Permanent Magnet Machine with a Dual Stator Structure
Authors: Shen Jie , Mei Lei
Published: December 2019

A new type of doubly salient permanent magnet machine with a dual stator structure is proposed. The motor is designed by staggering two stators by 45°on a 4/6 pole structure of double-salient pole motor. The motor has the advantages of high power density, small pulsation and high efficiency. The basic structure and working principle of the motor are introduced. The air-gap flux is calculated by the simple magnetic circuit method. The no-load magnetic field distribution, air gap flux density and permanent magnet Flux, back EMF, inductance characteristics of the machine are analyzed by using finite element simulation software. The inherent cogging torque of permanent magnet machine is analyzed. The simulation results verify the rationality of the new structure machine.
Research on Sidelobe Suppression Method in LFM Pulse Compression Technique
Authors: Wang Guofu , Tang Tiantian , Ye Jincai , Zhang Faquan
Published: December 2019

System sensitivity and range resolution are a pair of contradictory performance during target detection. In this paper, pulse compression is used to resolve the contradiction between range resolution and sensitivity. A frequency leak occurs in the compressed signal, so that weak targets of the matched filter output may be masked by adjacent strong target side lobes. It is common to suppress the side lobes by adding a window function. Through MATLAB simulation, it is found that when the signal-noise ratio is large, after adding the window function, the small target submerged by the large target side lobes cannot be detected. In this paper, an adaptive pulse compression (APC) technique based on minimum mean square error (MMSE) is used to suppress side lobes. The simulation proves that APC algorithm suppresses side lobes more effectively.
Dynamic Characteristics of Transformer Housing under Rigid/Flexible Foundation
Authors: Cao Hao , Zhang Wanfu , Gu Qianlei , Wu Xiaowen , Hu Sheng , Lu Ling , Peng Jiwen
Published: December 2019

This paper presented the dynamic characteristics of transformer housing under rigid/flexible foundation conditions based on finite element method. The deformation and stress distribution were analyzed due to interior excitations. The dynamic response for different stiffness coefficients was also investigated. Results show the maximum deformation of the housing occurs at the top of high pressure bushing with the value of 132.6μm. And the maximum equivalent stress occurs at the junction between the steel bar and the supporting steel frame with the value of 18.5 MPa. The velocity, stress and deformation at the measuring point show a periodic response, besides the response frequency is consistent with the exciting force. Foundation stiffness has a great influence on the dynamic response of the transformer housing. The amplitude of equivalent stress decreases with the decreasing foundation stiffness, while the amplitude of deformation shows an opposite trend.
Several Strategies for Anti-Multiple-Access Interference of Ground Equipment in Spread Spectrum Measurement and Control
Authors: Yang Liu , Jing He
Published: December 2019

In this paper, the inter-symbol interference problem of multi-objective mode for single-station measurement of ground equipment in spread spectrum measurement and control is obtained from the autocorrelation, cross-correlation, primitive polynomial selection method and three-object code between 10-level m-sequence and Gold code. Interference test and other aspects have been analyzed and discussed. Combined with the problem of small satellite star time-sharing signal level changes causing wrong lock and long time of re-trapping, the strategy of using ground-spreading measurement and control equipment is proposed.
Physics’ identification of formation process of wood polymer heat insulation material
Authors: Saldaev V A , Gusev V G , Koryakin A R
Published: December 2019

The article presents and describes in detail the physical picture of the process of forming the created wood-polymer insulation material in vacuum. It is proved that the developed material is a multicomponent system in which wood particles form a strong adhesive bond with a polyurethane foam matrix, characterized by complex physical and chemical reactions that occur in the process of interaction of all components of the system. Since the process of forming polyurethane foam occurs in the presence of wood filler, its influence on the process of gas phase formation during polymer foaming was studied. The main technological parameters affecting the formation of strong intermolecular bonds and the interaction of the components of wood-polymer insulating material with each other are revealed. In particular, it was found that the process of polymerization of polyurethane foam in the presence of wood filler under vacuum allows one not to deform or destroy the gas-structural elements during their formation. Also, basing upon the results of experimental studies, the dependence of the influence of wood filler moisture on the process of structure formation of the created material was established.
Influence of silica-containing materials surface properties on concrete structuring processes
Authors: Yadykina V V , Grichanikov V A , Akimov A E
Published: December 2019

The paper observes positive the influence of silica containing materials on cement systems. Practical and ecological parameters are shown. The data of a number and types of exchanges centers resulted from milling of industry-related materials are reported. Analysis of exchanges centers influence on cement hydration activity and “cement-mineral surface” contact zone interaction is provided. Theoretical justification of quartzitic sandstone and magnetic separation waste application as raw material for fillers is created. The influence of fillers surface on concrete structuring based on concrete plastic strength research is studied. It is determined that industry-related quartz-containing fillers application in amount 15 to 40% by weight of cement increases the plastic strength of cement paste and the speed of hydration processes. The period of structure formation of the cement stone is shortened, the intensity of hydrate accumulation processes increases. These data confirm the results of x-ray phase analysis of cement stone samples. A large amount of low and high basic capacity hydrosilicates is discovered during magnetic separation waste and quartzitic sandstone application. The use of the researched materials as fine fillers in cement concrete allows obtaining a composite with improved physico-mechanical characteristics and durability.
To issue of studying mechanism of increasing strength of porous ceramic crock
Authors: Mavlyuberdinov A R , Gaynutdinov I Kh , Evstigneeva Yu V
Published: December 2019

In our country at the modern stage of the development of constructional industry the necessity arises in qualitative ceramic wall materials. The use of this items provides durability, comfort and architectural expressiveness for constructions. In connection with what is an acute problem of use of “low-grade” clay raw material for production of high-quality wall ceramic products. The solution of problem is to activate clay raw materials in various ways. One of relatively simple, effective and economically expedient methods of the activation of clay raw material is mechanical activation. It is used to improve the quality of dense metamorphisized clay raw materials. But it is not enough, therefore it is offered to hold extra chemical activation by adding chemical additives in raw mixtures. The purpose of present research is to study mechanism of increasing the strength of the ceramic crock affected by the fluxing additive, imputed in raw mixtures proportion based on medium-plastic clay raw materials. To achieve the given purpose, it is necessary to solve the following tasks: a) to investigate influence of fluxing additives on rheological raw mix behavior; b) to study modification mechanism of changing the properties of ceramic crock by adding fluxing additive into the raw mixtures.
Heavy concrete with mineral additive tripoli
Authors: Lukuttsova N P , Golovin S N , Artamonov P A
Published: December 2019

The research results of the effect of active mineral additive tripoli of the deposits of Grishina Sloboda of the Bryansk region on the strength of heavy concrete are presented in the article. The chemical composition and structure of the sedimentary rock tripoli are studied. It is found that the tripoli grinding to the specific surface area of 340 m2/kg leads to the production of concrete class B35 with its content of 5% and class B30 with its content of 10%. The extreme dependence of the concrete strength on the tripoli content after 7 and 28 days of hardening is established. It is shown that the diminution in the sand fineness modulus from 2.87 to 1.14 reduces the concrete strength with 5%-tripoli addition from 38.9 MPa to 21.8 MPa, and with its content of 10% from 36.3 MPa to 20.4 MPa. The dependence of heavy concrete strength after 7 and 28 days of hardening on the content of its components was determined by the method of mathematical planning of the experiment, it allows predicting the values of this indicator when varying the composition of the concrete mixture.
Improving crack resistance of concrete when using expanding cements
Authors: Samchenko S , Krivoborodov Yu
Published: December 2019

The possibility of enhancing the basic properties of concrete products by using a mixture of Portland cement and sulfoalumoferrite clinker as a binder is considered. It was established that upon hydration of the binder, aluminate and ferruginous ettringite are formed, which increase the strength properties of concrete during normal hardening and thermal and wet processing by increasing the strengthening structure. The main sign of hydration of sulfoalumoferrite clinker is the stability of ferrous ettringite, which ensures the compaction of the concrete structure. The dense structure of the structure of concrete, especially the contact zone, when using sulfated clinker, ensures the non-shrinkage of concrete and eliminates shrinkage deformations and, thereby, increases the crack resistance of concrete samples.
Interrelation of rigidness of triangular cross-sections under bar torsion with conformal radii relation
Authors: Korobko V I , Korobko A V , Lygina J E
Published: December 2019

The investigated problems of interrelation of the given geometrical rigidness of bars cross-sections of pure torsion with the geometrical characteristic of cross-sections – the relation of the internal conformal radius to the external conformal radius are covered in the article. Formulas for calculation of values of internal, external conformal radii and their relations for arbitrary, isosceles and rectangular triangles are given and the approximating functions for definition of these geometrical characteristics for triangles of any form are constructed. The graphic analysis of the obtained values shows that all variety of the relations of conformal radii presented graphically depending on one of the triangle corners falls into two subsets. One of them includes all variety of acute triangles, which is limited to isosceles acute triangles and rectangular triangles, and another one is limited with isosceles obtuse triangles and rectangular triangles. The graphic analysis of the whole variety of the known values of the given geometrical rigidness of triangular cross-sections at torsion, presented depending on one corner of a triangle, demonstrates that this geometrical characteristic is functionally connected with the relation of conformal radii; the corresponding approximating functions have linear character.
Experimental determination of yield in beam-to-column flange connections
Authors: Son M P
Published: December 2019

The paper describes a universal test bench, designed to conduct full-scale studies of the strength and stiffness of joints of building structures. The paper present the results of full-scale tests of the joints of beam flanged connections with columns in the elastic and elastoplastic stage with the determination of the dependence of their yield on the value of static loads. The study was conducted on 12 models with both one-sided joining of the beam to the column, and with two-sided, for which the flange thickness, resistance class and the controlled tension of the bolts, loading scheme were varied. The experiments were carried out according to a multifactorial plan until the destruction of the models. According to test results, 4 characteristic trilinear diagrams were obtained for dependence of the angles of rotation versus bending moments. The obtained results can be used in the design of flange connections and during the verification of their design models.
Time analysis of dynamic response of spatial frame building under action of seismic forces
Authors: Artemyeva L M , Potapov A N , Razzhivina A V
Published: December 2019

An analytical approach to the calculation of the spatial framework for the action of seismic forces is considered. This approach is an extension of the previously proposed time analysis method and used to determine the dynamic response of a dissipative structure modeled by a discrete computational scheme. Mathematical models of oscillations are given: the differential equation of motion of a dissipative system, the matrix characteristic equation with a quadratic input parameter and the fundamental matrix that carries out the relation between the differential and characteristic equations. Accounting for internal friction is carried out in accordance with the model of non-proportional damping. The structure of the vector of seismic forces generated by earthquake accelerogram data is shown. The kinematic and force characteristics of the system are determined by the equations of the seismic reaction of the framework at any time. The parameters of the calculated dynamic model (stiffness, damping and mass matrices’ elements) are constant on the entire interval during the calculation of elastic seismic response. Dynamic reaction equations are constructed in an analytical form based on the Duhamel integral. An example is given of analyzing vibrations of a 3-storey spatial framework under the action of a seismic load.
Geometric rigidity of torsion of thin-walled pipes: theory and experiment
Authors: Korobko A V , Kalashnikova N G , Tyurin V O
Published: December 2019

Thin-walled rods as structural elements of buildings, structures and machines that absorb torsion deformations are widely used in construction and engineering. Development of analytical methods for solving the problem of torsion of rods of non-circular cross section is one of the most important modern problems of construction mechanics. When solving torsion problems, the geometric rigidity of the section Ik
is primarily determined. The analysis of the considered literature sources showed that the study of the problem in question using the isoperimetric properties of cross-sections of rods is very effective. In the present paper, for thin-walled pipes with an arbitrary convex contour and constant wall thickness, the authors obtain calculation formulae that associate the reduced geometric rigidity of the cross-sections of the pipes Ik
with their form factor. It allows formulating the isoperimetric properties of the parameter under study depending on the shape of the pipe sections, and using geometric methods to determine the geometric rigidity of the cross-sections of pipes of arbitrary shape and a convex contour. The article also contains the results of experimental studies of triangular pipes confirming this isoperimetric relationship of the reduced geometric rigidity of pipes with the form factor.
Fatigue behavior of concrete in cyclic low-temperature impacts
Authors: Pinus B I , Kalashnikov M P
Published: December 2019

Wear and tear of concrete and reinforced concrete structures in harsh climatic conditions is analyzed as a fatigue process with various cumulative failures. For the criteria of their prediction, it is proposed to use dynamic models containing the kinetics of changes of informative and sensitive indicators of the constructive properties of concrete during cyclical freezing and thawing (CFT). An experimental-analytical generalization of the measurement of the following indicators is presented: strength, components of deformations, cracking, and the energy potential of concrete destruction during the exhaustion of its frost resistance. It is proposed, as a first approximation permissible under the conditions of the onset of fatigue parametric failures, to take the level of external temperature and humidity effects equivalent to (ultimately) 85 ÷ 90% of the frost resistance mark.
On possibility of local suppression of natural vibrations of elastic structures under shock effects
Authors: Sobolev V I , Zenkov E V
Published: December 2019

Manifestations of shock effects in the form of subsequent natural oscillations of structures for various purposes can be different in intensity, in directions of oscillatory processes (forms of natural oscillations) and in frequencies involved in oscillatory processes. At the same time, the tasks of suppressing or reducing the intensity of oscillations in certain specified directions have obvious relevance. Suppression of forced stationary oscillations in certain specified directions (obtaining zero amplitudes of oscillations in these directions) is possible by forming dynamic quenching effects implemented as the systems that satisfy a number of formalized requirements for the design parameters of such systems. In earlier papers of the authors it was shown, that the realization of such effects in the processes of natural oscillations is associated with the formation of conditions for the multiplicity of natural oscillations of elastic systems. In the proposed paper the conditions for the formation of the multiplicity of natural frequencies of multiply connected finite-dimensional systems of small dimension are considered, reflecting the specific manifestation of the multiplicity of natural oscillation frequencies of finite-dimensional dynamic systems of arbitrary dimension, the properties of such systems are applied to the suppression of natural oscillations in specified directions.
Energy efficient building for arctic regions
Authors: Inzhutov I S , Zhadanov V I , Melnikov P P
Published: December 2019

The relevance of this topic is stipulated by the sharp changes in climate in the Arctic region, characterized by such factors as increased winds and blizzards, the impact of the stone particles from the quarries near industrial centers, low temperatures, temperature rise, decrease in the area and thickness of ice, melting of the Greenland ice sheet. In 2007-2008, satellite observations showed that its area reached the minimum for 30 years of observations, the next minimum was registered in 2012. In many existing Northern cities and towns, a serious problem with the functioning of housing and communal services is beginning to emerge: emergency and dilapidated housing exceeds the average for Russia. A significant number of standard projects, not adapted to the extremely harsh Northern conditions, requires frequent repairs, excessive heat and energy, which leads to a huge expenditure of funds. These factors determine the need to design new types of buildings in high-latitude regions
Supporting structures of machine-building enterprises of 1920-1930
Authors: Buzalo N A , Kozhihov A G , Tsaritova N G
Published: December 2019

The article provides an analysis of the design solutions of industrial buildings of the engineering industry, that were built in 1920-1930. This period is characterized by the use of monolithic and precast concrete elements as the supporting structures of the frames of industrial buildings, because of the need for super-efficient use of steel. Low-carbon steel of low grades was used as reinforcement. Space-planning and constructive solutions of buildings of this period are not peculiar to later periods of construction. The purpose of research is to identify and describe the characteristic features of the frameworks, its inherent defects and damage of the supporting elements, and ways to eliminate them. As a rule, the considered buildings are characterized by increased spatial rigidity and stability, provided by the rigid coupling of columns with foundations, monolithic transverse elements and longitudinal crossbars. This explains the safety of supporting structures during long periods of operation, low sensitivity to the sediments of the supports during deformations of the soil base. Enclosing structures, self-supporting walls on almost all the objects surveyed have become inoperable. To continue the exploitation of such buildings, almost complete replacement of envelopes, repair and strengthening of local damage of supporting reinforced structures is required.
Modelling and numerical solution of problems of structural mechanics with unilateral constraints and friction
Authors: Lukashevich A A , Lukashevich N K
Published: December 2019

The article deals with the problems of calculation of elastically deformable systems with unilateral constraints and Coulomb friction. For the numerical solution of the problem, the finite element method is used, the contact interaction is modeled by means of the contact finite elements (CFE) of the frame-rod type. The basic relations and statements of static and dynamic contact problems for the interacting elastic bodies are given. To comply with the limitations under the conditions of ultimate friction-sliding, the method of compensating loads is applied. On the basis of the proposed discrete contact model and step-by-step loading schemes, the numerical algorithms are developed, which allows calculating structures with unilateral constraints and Coulomb friction, both under static and dynamic loads, as well as taking into account the different contact conditions that approximate the calculation scheme to the real operating conditions of a structure or construction. With the help of the proposed approach, numerical solutions of the problem of contact of the structure with the base under dynamic load are obtained and analyzed.
Behavior of compressed concrete in a glass fiber-reinforced shell
Authors: Krishan A L , Chernysova E P , Astafyeva M A
Published: December 2019

The paper presents a theoretical study of the structural resistance of short compressed concrete elements in a glass-fiber reinforced shell. The methodology is based on a nonlinear strain model of how this element reacts to incremental loading. What makes computing such structures difficult is the need to account for the continuously changing lateral shell pressure on the concrete core. Lateral pressure keeps increasing due to changes in the concrete-core and glass fiber-reinforced shell lateral-strain coefficients, causing greater stress in the material. This paper is the for to propose formulas to account for such changes and measure lateral pressure for any load on such a structure. It also outlines practical guidelines on computing the strength of short compressed concrete elements in a glass fiber-reinforced shell.
Research on problems of panel buildings
Authors: Mavlyuberdinov A R , Mukminov R N
Published: December 2019

The purpose of the study is to identify and reveal the main problems arising from the operation of panel buildings, to determine the location of the leakage of joints in panel buildings and to analyze the economic effect of a thermal imaging survey with subsequent repair. The main results of the research consist in analyzing the types of joints of large-panel buildings and their features as well as in conducting the thermal imaging survey of interpanel joints for heat loss and identifying the most problematic areas, according to the results of which heat loss is formed through the vertical and horizontal joints between the panels, as well as at the junction points of the windows. According to the results, the economic effect of the thermal imaging survey shows that the additional costs of paying for heat before overhaul due to the deterioration of the thermal protection quality are many times greater than the cost of the thermal imaging survey, taking into account the additional costs of eliminating thermal protection defects.
Numerical modelling of the reinforced concrete beam shear failure
Authors: Budarin A , Alekhin V , Avdonina L
Published: December 2019

Shear failure of reinforced concrete members is a complex process, which depends on a huge number of different factors. It is less investigated compared to other types of failure. Modern numerical methods, including finite-element method, allow predicting complex behavior of different structures when loaded. This article deals with the detailed nonlinear analysis of the shear failure of the reinforced concrete beam, using Drucker-Prager yield criterion. The results generated based on the finite-element model, developed in ANSYS software, were compared to the results of a laboratory experiment. In addition, the main advantages and disadvantages of this approach were described.
Some aspects of construction industry development in 2018
Authors: Peshkov V V
Published: December 2019

The construction industry, despite the economic difficulties, has long been one of the most stable and dynamic sectors in the Russian economy. Being one of the main sectors of the economy of each country, the construction industry performs the main task - the introduction of new, reconstruction of old objects, both residential and commercial purpose. The development of the construction industry is among the most important tasks of the government of all countries. Analysis of the economic situation in the construction industry can identify problems and identify areas of development of the construction industry. The article describes the indicators reflecting the efficiency of the industry in Russia and in the Irkutsk region. The construction industry is suffering from a skills shortage, slim margins and low productivity, but help is at hand in the form of new technologies and innovative materials. Measures aimed at supporting the development of the construction industry by minimizing the existing problem areas are proposed. The author think the construction industry should not be overlooked in this day and age. It is necessary to develop a “road map” for the development of the construction industry in the coming years, which will determine the priorities and main directions of the state regional policy in the construction sector, tasks, activities and development targets.
Determination of design layer of rainfall for design of treatment facilities of surface runoff
Authors: Palagin E D , Gridneva M A , Bykova P G
Published: December 2019

The article assesses the influence of the initial data and the duration of observations on the calculated value of the sediment layer, which determines the performance of treatment facilities of surface runoff. At design of these constructions drain volume from a settlement rain is found. The error introduced by the grouping of initial data depending on the accepted gradation of intervals is determined. The daily layer of precipitation from low-intensity frequent rains with a period of a single excess of the calculated intensity of 0.05-0.1 years was determined (for the conditions of Samara). Recommendations on the choice of initial data in the design are given.
Study of aerodynamics of stream flow in server rooms using numerical modeling
Authors: Trubitsyna G N , Surovtsov M M , Indykov V S
Published: December 2019

This paper analyzes various schemes of air exchange in server rooms. Top-down and down-top vertical cooling schemes for small server rooms using local AC systems were analyzed. Numerical models were developed for the study of heat and mass transfer and server aerodynamics, which make it possible to evaluate the cooling efficiency of electronic equipment when placed in an arbitrary configuration. To study the thermal and velocity fields, numerical simulation of the stream flow processes was performed using the FlowVision software. This paper shows the advantage of the selected air-conditioning scheme compared to the existing ventilation system. Modeling results may be used for designing small server rooms.
Rotunda church in Russia as typological phenomenon
Authors: Tereshina O B
Published: December 2019

The article describes results of a complex research, in the course of which the main stages of origination and formation of a rotunda church as a rare type in the history of the world’s and Russian architecture have been determined. The main groups of rotunda churches in the world architecture (7 types) and Russian architecture (9 types) have been identified together with criteria of their classification and typological characteristics, the chronology frames of formation of certain types. Space-planning and compositional decisions in designs of rotunda churches have been analyzed based on their types in the context of typology developed by the author. The types of rotunda churches and individual monuments of rotunda church architecture from the world architecture history, which served as a source of inspiration for architects in Russia, are considered. Features of Russian rotunda churches connected with the Orthodox traditions and national traditions of church architecture were identified. The examples of rotunda churches around the world, constructed within the multi-age period between the 6th century BC till the 19th century, and of Russian rotunda churches constructed within a short period from the end of the 17th century and till the middle of the 19th century, are made.
Approaches to design of navigation systems in public institutions
Authors: Surina L
Published: December 2019

The article considers specificities of design of navigation systems in public buildings and institutions, transformation of verbal information into a sign, symbol, pictogram, as well as simulation of versatile structures of navigation system carriers and their experimental application. Comparative analysis of principles of designing navigation systems in public buildings and institutions, intended to systematize a big volume of information transformed into a symbol, sign or pictogram, which favors for its quick perception, is carried out. The article considers the main principles of design of navigation systems. The research relevance is determined by the necessity to create versatile navigation systems for the improvement of communication in various public institutions.
Fractal properties of settlement system as factor of its sustainability: Ural in the 18th–20th centuries
Authors: Bystrova T J
Published: December 2019

The thoughts by N. Salingaros on sustainable design, translated and introduced into scientific discourse by the author of the paper, served as a basis for primary analysis of the layout of a small industrial town and the settlement system of the industrial part of the Urals. Invariable features of the town layout have been reconstructed based on the materials by W. de Gennin and modern historical and cultural studies. The paper shows the elements of fractality and self-similarity in the layout of small industrial towns and in the Ural settlement system, which correspond to the parameters established by N. Salingaros. A conclusion is made about sustainability as an additional internal resource of the settlement system in the region.
Integration of industrial territories into the urban environment
Authors: Korosteleva N V , Rastyapina OA
Published: December 2019

Industrial territories have high town-planning potential, their renovation and revitalization improve town-planning, ecological, visual and other characteristics, the cities allow creating an organic architectural and landscape environment. The question of reorganization of the urban environment by renovation of industrial territories came under the spotlight at the end of the XX century. Now this subject is actively investigated in the works by many authors of Europe and Russia. Especially it belongs to questions of a complete solution of problems of industrial territories with the objects adjoining the central part of the city and also research of the questions issues connected with influence of industrial facilities on formation of architectural and spatial composition of the city. At the same time identification of ways of harmonization and development of the urban environment by renovation of industrial territories is one of relevant tasks when forming the concept of sustainable development of the city. In the article the issue of integration of the abandoned industrial territories into the urban environment is considered. Several directions of adaptation of industrial heritage to a modern context of the city are offered.
Aeration mode of main streets in high-density development
Authors: Balakin V V , Antyufeyev A V , Sidorenko V F
Published: December 2019

The aeration mode of urban areas in design practice is established for different geographic regions depending on the initial wind speed taking into account the human thermal state and the quality of atmospheric air. The purpose of the research is to assess the design, building and geometric parameters of the city streets influence on the airflow transformation and the atmospheric air pollution level. Based on the research results in full-scale conditions and on residential units’ models, the features of the main streets aeration mode formation and the gas contamination level were revealed. It was found that the variations in wind speed and the distribution of pollutants in street canyons with a change in their width are connected with the formation of buildings flow regimes: along the envelope, turbulent-jet and isolated ones. The planning conditions that contribute to the formation of a stable vortex connected with the closed circulation of impurities in the street canyons were determined. Town-planning hygienic recommendations are given to regulate the streets aeration regime in order to ensure standards for the content of residential units’ atmospheric pollution in the air, to protect urban residents from cold strong winds or to maintain the initial wind speeds in residential units.
Renovation of mass residential development in late 1950s-early 1970s in St. Petersburg: problems and perspectives
Authors: Yankovskaya Y S , Vaytens A G
Published: December 2019

This article is devoted to the problem of transformation of morally and physically outdated mass residential development of the 1950-60-ies of St. Petersburg. This problem is particularly acute for the first series of panel dwelling development, the life of which is coming to an end. In this article the concept of space development of the residential panel dwellings of the “first generation” (the 1950-ies – the 1960-ies), based on the modern tendencies and the European experience is presented. The important points are the permeability of residential development, focus on the formation of social contacts; the concept of yard-garden and active implementation of the green component, the cultivation of pedestrian and road traffic.