Within the plane-stress state the problem of a high-speed rotating disk being under side pressure is considered. Within the model of a perfect rigid-plastic body and the Mises yield criterion the allowable boundaries of external parameters have been defined. Within the model of a perfect elasto-plastic solid and the Mises yield criterion the limit state of the disk has been considered. The displacements and the deformations are assumed to be negligible quantity; deformation plasticity theory is chosen. The problem of defining the stresses is ecstatically determined. The displacements are determined together with the stresses. In order to define the displacements as single-valued within the model of a perfect elasto-plastic solid when the disk is in the limit state it is chosen the condition that the plastic deformations inside the disk side surface are equal to zero. For the model of a perfect rigid-plastic body in order to define the displacements as single-valued the displacements values inside the side surface of the disk are needed to be determined. Plots of numerical calculations for the stresses, the deformations, the displacements and the stress vector hodograph have been introduced.
Keywords: the plane-stress state, Mises yield criterion, the limit state, a rigid-plastic body, an elasto-plastic solid, a rotating disk, a stress vector hodograph
The paper focuses on energy efficient reconstruction of construction systems by means of their upward extension using modular spatial structures. It is further noted that the existing contradictory definition of the term “modular structures” necessitates classifying modular structural elements by spatial dimension, type and size, weight, degree of prefabrication, constructability and environmental safety. A list of the world’s leading manufacturers is provided featuring modular spatial structures to be used in the construction of new buildings and reconstruction of existing buildings. Also, the paper underlines the importance of using added stories in making modular roof structures of lightweight metallic structures (LMS) and lightweight thin-wall steel structures (LTSS) and provides an overview of the main types of modules, pointing out the key benefits of modular structures.
Keywords: modular building structures, energy efficient reconstruction, upward construction, structural and non-structural modules, constructability
The analysis of the organization of passenger transportation in long-distance traffic in the direction of Center-South. It is known that the transportation of passenger and freight trains on the Russian railway network is carried out on the same tracks, and the dynamics of their growth is ahead of the development of the capacity and carrying capacity of the railway direction in question. In this regard, foreign and Russian experience in the development of growing volumes of passenger and cargo transportation in conditions of infrastructure constraints was studied. The measures of step-by-step development of high-speed and high-speed movement of passenger trains are proposed. The technique of calculation of efficiency of the organization of the considered types of movement of passenger trains on the direction Center-South is resulted.
Keywords: passenger transportation, prospective volumes, infrastructure constraints, methods of development, high-speed transportation, efficiency of high-speed traffic
Finite state machines, being a mathematical abstraction, allow you to perceive information from the control object, process it and give signals to control the object. The disadvantages of the representation of complex production systems by a set of finite state machines include the complexity of carrying out logical and set-theoretic operations on them and the complexity of describing the parallelism that occurs in the operation of complex production systems. When specifying a finite state machine in the matrix–predicate form, due to the information redundancy, it is possible to avoid these difficulties. Matrix–predicate method allows you to uniquely set the finite state machine square matrix, which makes it possible to use the methods of the theory of matrices during the set–theoretic operations on them and it is possible to avoid isomorphism. The paper presents the developed methods of representation of a finite state machine using a multi-place predicate, which greatly simplifies its task.
Keywords: finite state machine, graph, matrix, predicate, algorithm, matrix–predicate method, graph incident, tuple, Cartesian product, complex production systems
The article presents the results of studies of the plastic properties of heated porous powder materials in the sediment tests. A technique for determining the transverse dimensions of porous billets is given, which provides their defect-free dynamic hot pressing in the matrix.
Keywords: plastic property of the material, the study of deformability, ductility of the material, transverse deformation, heating temperature, calculation method, dynamic hot pressing, powder billet, transverse size of the workpiece and the matrix, the initial siz
The article presents the results of studies of the plasticity of heated powder materials from the initial porosity during the sediment tests. It was established experimentally that for the selected deformation conditions, the powder of iron powder PZh4S2 with the initial porosity of 20–30% has the greatest plasticity during the draft
Keywords: plasticity, heating temperature, density of samples, specific work of deformation, sediment, measurement of samples, coefficients of height and transverse deformation, porosity, powder billet
Mathematic modeling of the state of a thin round disk being heat and force affected is performed. In the central part of the disk the homogeneous field of temperatures is formed. Within the deformation theory of a perfect elasto-plastic solid the quadratic plasticity condition is chosen. The relationships between the radius of the disk, the temperature of the central part of the disk and the external pressure which defines the appearance of plastic zones have been established. For different values of external parameters of the model the stress vector hodograph and the plots of stresses and equivalent stresses have been introduced.
Keywords: mathematic modeling, an elastic-plastic solid, the plane-stress state, the deformation theory, thermo-elasto-plasticity, a high-speed rotating disk
The article deals with the processes of separation of thin films of oil liquids on the basis of rotary-belt type devices. The analysis of interaction of liquids and working body is made. The model of formation of oil films and their separation is described. the Studies create prerequisites for the development of engineering methods for calculating the design and operating parameters of the rotor-belt device for the formation of emulsion films and cleaning water surfaces from oil films, which is of great environmental importance.
Keywords: emulsion, film, apparatus, oil stain, viscosity, water surface cleaning
The article provides a technical solution to increase the bearing capacity and reduce the deformability of the subsiding base of a house. The design features of the fixed base and enclosing rows of bored piles are described. The article was published in the framework of the program of the International Forum "Victorious may 1945".
Keywords: row, anchoring grounds, reinforcement, soil, cement, cementation, directional hydraulic fracturing
In work area of application for quantitative metrics of databases are considered. Quality control of the database scheme is impossible without numerical indicators. Metrics of the database can be calculated it is automated that guarantees the accuracy and recurrence of such measurements. In article the model for assessment of complexity of the physical scheme for relational database based on metrics of the table of the database is offered. For the offered model by using the method of T. Saati, received coefficients which consider extent of influence of each metrics on complexity of the database. On the example of real projects for databases quantitative measurements of their metrics in MySQL are executed. The comparative analysis of the results obtained for the model of complexity estimates for various projects of physical schemes for databases and the amount of information contained in sql-scripts of these databases are described.
Keywords: evaluation of complexity, database, physical schema, model, SQL, entropy
“The article was published as part of the implementation of the program of the International Forum“ Victory May 1945 ”.The article deals with the problem of a reasonable redistribution of the pedestrian and transport space of the street, a balanced use of the territory in order to more efficiently regulate traffic and pedestrian flows, as well as to take into account statistical data on the use of street space, taking into account the time of day, the location and methods of using this space
Keywords: pedestrian space, sidewalk, transport space, pedestrian, parquet, design of architectural environment, urban scenario
Despite numerous advantages, green construction has not yet acquired significant proportions, since modern environmental technologies in construction lead to increased costs, and legislation is also not being adapted to new certification systems. This article outlined the main objectives of "green" construction. Considered the most important principles on which it is based. Analyzed the modern "green" standards for environmental performance of buildings, discussed in detail the methods for determining the rating of a building on specific scales. The advantages and disadvantages of environmental standards were also noted, groups of organizations in the field of “green” construction in Russia were considered.
Keywords: environmental technology, green building, green standards, energy saving, energy efficiency, energy consumption, green building, renewable energy sources
The article presents the method of appointment of the composition of the molding mixture, which is based on the calculation and experimental approach. The results of the research served as the basis for the practical implementation of the proposed technological method of increasing the durability of small-sized products made of fine concrete. The article was published in the framework of the program of the International Forum "Victorious may 1945»
Keywords: workability of concrete mix, water-cement ratio, grain composition, raw materials, concrete, acidic medium, sodium sulfate, durability, small products, classification of defects, vibration mixing, technological methods
The article describes the method of substantiation of the parameters of strengthening the soil base of a house by cementation through directional hydraulic fracturing. Also describes the work in the laboratory, which allowed to choose the necessary compositions of the cement mixture.
Keywords: reinforcement, soil, comentaron, cementation, directional hydraulic fracturing
The article deals with the problems and features of Informatization of higher education. The problems of information technologies in the educational process are presented. The main advantage of it is that they contribute to the creation of an effective multi-sensory interactive learning environment with great potential for use by teachers and students. The factors influencing the process of Informatization of educational institutions are analyzed. In order to achieve positive results of the use of information technologies in training, it is proposed to introduce new subject programs in the educational process, which will allow to determine the methods of teaching and the conditions of the educational process. The use of subject programs will provide the user with the opportunity to build their learning algorithm.
Keywords: information technologies, education, communication technologies, problems of training, features of training, programs, factors influencing process of Informatization of educational institution, conditions, advantages of information technologies