ANALYSIS OF DEVIATIONS AND MOUNTING STRESS-STRAIN STATE IN THE TRANSVERSE DIAPHRAGM OF CYLINDRICAL ROOF STRUCTURE

Vestnik MGSU 11/2017 Volume 12
  • Bondarev Aleksey Borisovich - Joint Stock Company "Matrosov Mine" (JSC "RiM") engineer on metal constructions, Joint Stock Company, Joint Stock Company "Matrosov Mine" (JSC "RiM"), 12 Proletarskaya str., Magadan, 685000, Russian Federation.
  • Yugov Anatoliy Mikhaylovich - Donbas National Academy of Civil Engineering and Architecture (DonNACEA) Doctor of Technical Sciences, Professor, Head of Construction Engineering and Management Department, Donbas National Academy of Civil Engineering and Architecture (DonNACEA), 2 Derzhavina str., Makiivka, Donetsk obl., 86123, Ukraine.
  • Garanzha Igor’ Mikhaylovich - Moscow State University of Civil Engineering (National Research University) Candidate of Technical Sciences, Associate Professor, Department of Metal Structures, Moscow State University of Civil Engineering (National Research University), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation.
  • Shchukina Liliya Sergeevna - Donbas National Academy of Civil Engineering and Architecture (DonNACEA) graduate student, Construction Engineering and Management Department., Donbas National Academy of Civil Engineering and Architecture (DonNACEA), 2 Derzhavina str., Makiivka, Donetsk obl., 86123, Ukraine.

Pages 1248-1260

Subject: In this article we review and analyze structural forms and methods for accounting for deviations in metal roof structures. The article also reviews and analyzes previously performed works and methods for accounting for deviations in the design of metal structures. Research objectives: analysis of deviation values and mounting stress-strain state (MSSS) of the transverse diaphragm of a single-chord hinge-rod metal shell. A comparative calculation of deviations and calculation results analysis was made on the example of a transverse diaphragm of a single-chord hinge-rod metal shell of the roof structure for different technological assembly-mounting schemes: from the supports to the arch center, and vice versa, from the arch center to its supports. Materials and methods: geometrical method for determining deviations is implemented in the the author’s computer program - computing complex of dimensional analysis (CP CCDA); method of finite elements (FEM) is used for determining mounting stress-strain state and is implemented in SCAD 11.5. Results: The calculation and analysis of the mounting stress-strain state (MSSS) of the diaphragm was performed. Out of two assembly schemes considered in the paper we recommend the second technological scheme of assembly-mounting and also possible ways of compensation for the assembly deviations in the end diaphragm of the cylindrical roof structure of the hangar. We suggest possible options for modeling deviations of individual members of rod systems for several types of profiles and we propose possible cross sections of diaphragms of arched roof structures. Conclusions: the methodology for determining the installation deviations and the method for determining the MSSS, proposed in this article, can be used to determine deviations in a variety of large-span hinge-rod metal structures.

DOI: 10.22227/1997-0935.2017.11.1248-1260

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NUMERICAL AND FULL-SCALE EXPERIMENTS OF PRESTRESSED HYBRID REINFORCED CONCRETE-STEEL BEAMS

Vestnik MGSU 3/2018 Volume 13
  • Zamaliev Farit Sakhapovich - Department of Metal Structures and Testing of Structures, Kazan State University of Architecture and Engineering (KSUAE) Candidate of Technical Sciences, Professor, Associate Professor, Department of Metal Structures and Testing of Structures, Kazan State University of Architecture and Engineering (KSUAE), 1 Zelenaya st., Kazan, 420043, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Pages 309-321

Recently, civil buildings are increasingly using composite reinforced concrete and steel (RCS) structures (beams, slabs, columns). Prestress in RCS structures has not yet found such a spread as, for example, in reinforced concrete and metal structures, although its use is known from technical sources. The present article is devoted to the evaluation of the stress-strain state of prestressed RCS beams. The procedure and results of computer modeling of the response of composite RCS beams consisting of steel I-beam, anchors, prestressed reinforcement and concrete are given. Two variants of arrangement of prestressed reinforcement are considered. According to the data of numerical studies, full-scale samples of beam models were made and their tests were carried out. The article presents the test procedure, the results of experimental studies in the form of graphs, diagrams. At the end of the article, analytical expressions are given for analysis of composite RCS beams of the described cross-section. Results of calculations, comparison of the results of numerical and full-scale experiments are presented. Subject: based on computer simulation and full-scale experiments, the stress-strain state of prestressed composite beams was investigated. Beams were studied with the arrangement of prestressed reinforcement along the I-beam flanges and along the envelope of the bending moment diagram. Research objectives: analyze the stress-strain state of beams, identify effectiveness of the arrangement of prestressed reinforcement. Materials and methods: for full-scale experiments, steel I-beams with lateral cavities filled with concrete were adopted, rod reinforcement was used as a prestressed reinforcement, and a dynamometric key was used for prestress (preload). ANSYS software package was used for computer modeling. Results: the computer simulation data of the stress-strain state of beams is obtained. The results are used for making full-scale samples. The obtained results of computer simulation are compared with the data of full-scale experiments. Conclusions: essential features of the response of prestressed composite beams are studied from numerical modeling, in-situ experiments and analytical calculations. The proposed calculation method gives a good match with the experimental data.

DOI: 10.22227/1997-0935.2018.3.309-321

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COMPUTER MODEL OF HEAT PUMP WITH A CONSTANT ROTATION FREQUENCY OF A SCROLL COMPRESSOR SPIRAL

Vestnik MGSU 4/2017 Volume 12
  • Timofeev Daniil Victorovich - Moscow State University of Civil Engineering (National Research University) (MGSU) Postgraduate Student of Department Heating and Ventilation, Moscow State University of Civil Engineering (National Research University) (MGSU), 26 Yaroslavskoe shosse, Moscow, Russian Federation, 129337.
  • Malyavina Elena Georgievna - Moscow State University of Civil Engineering (National Research University) (MGSU) Candidate of Technical Science, Professor, Professor of Department Heating and Ventilation, Moscow State University of Civil Engineering (National Research University) (MGSU), 26 Yaroslavskoe shosse, Moscow, Russian Federation, 129337.

Pages 437-445

Heat pumps are used for heating buildings and structures. Determination of thermal characteristics of a heat pump in modes other than the nominal ones is associated with certain difficulties, since, in the cold climate of Russia, these characteristics, indicated by the manufacturers in accordance with the requirements of the standards, will differ for the worse. In study, the following purposes were set: сomputer simulation of the water-water or water-glycol heat pump and its representation in the form of a simulation system of two heat exchangers and a scroll compressor; conducting numerical calculations of the geothermal heat supply system, estimating its efficiency both under different configurations and operate modes using computer simulation. The software package for computer simulation is written in the language of scala, both Nelder-Mead and Levenberg-Marquardt algorithms are used to obtain model parameters from the compressor and heat pump data, the method of Gold Cross Section is used for one-dimensional minimization. The presented simplified model for heat pump parameter estimation aims to selection of pump size and simulation its operation during year. While the scroll compressor model is made to be comprehensive, the other parts of heat pump model were simplified. The resulting model consists of individual compressor models, evaporator heat exchangers, and refrigerator. The compressor model takes into account the useful overheating of the refrigerant, work on various refrigerants. Models of heat exchangers are simplified. The model parameters are calculated from the data specified by the manufacturers of heat pump and compressor equipment. The model approximates the data of the equipment manufacturer and, therefore, can be used as an element of the geothermal system in energy modeling programs. Using the model, it is also possible to determine the actual characteristics of the heat pump operation in modes other than the nominal one and with the use of different refrigerants. Another application of the obtained results is the identification of unscrupulous manufacturers indicating fictitious data in their catalogs. Obtained model can be extended by including other refrigerants, variable compressor motor rotation frequency, and more precise implementation of the other heat pump parts.

DOI: 10.22227/1997-0935.2017.4.437-445

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Numerical and experimental investigations of steel-concrete beams with thin-walled section

Vestnik MGSU 1/2019 Volume 14
  • Zamaliev Farit S. - Kazan State University of Architecture and Engineering (KSUAE) Candidate of Technical Sciences, Professor, Associate Professor of Department of Metal Structures and Testing of Structures, Kazan State University of Architecture and Engineering (KSUAE), 1 Zelenaya st., Kazan, 420043, Russian Federation.

Pages 22-32

Introduction. Conducted is to the evaluation of the stress-strain state of the steel-concrete beams with thin-walled section. In recent times, steel-reinforced concrete structures have become widely used in civilian buildings (beams, slabs, columns). Thin-walled section have not found wide application in steel concrete structures, unlike steel structures. Presents the results of numerical studies of beams consisting of concrete, anchors and steel beams. Two investigating of the location of anchors are given. Numerical investigations are presented of steel-concrete beams with thin-walled section based on numerical studies. Testing procedure and test result are given. Results of calculations, comparison of numerical and experimental studies are presented. Materials and methods. For full-scale experiments, steel I-beams with filling of side cavities with concrete were adopted, screws are used as anchor ties, with varied both the lengths and their location (vertically and obliquely). As steel curved C-shaped steel profiles were used steel profiles from the range of the company “Steel Faces”. ANSYS software package was used for computer modeling. A total of 16 steel concrete beams were considered, for which the results of strength and stiffness evaluation were obtained in ANSYS. Results. The data of the stress-strain state of beams on the basis of computer simulation are obtained. The results are used for the production of field samples. Data of computer simulation are compared with the indicators of field experiments. Conclusions. The stress-strain state of steel-concrete structures was studied on the basis of numerical and experimental data. The proposed calculation method gives good convergence with the experimental data. Anchor connections made from self-tapping screws can be used in studies for modeling in steel-concrete beams structures and other anchor devices, ensuring the joint operation of concrete and steel profiles in structures.

DOI: 10.22227/1997-0935.2019.1.22-32

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Simulating pseudotruss excavating part of excavators

Vestnik MGSU 3/2019 Volume 14
  • Zotov Oleg A. - Pneumax engineer, Pneumax, 30 vlad. Communal proezd, Khimki, 141400, Russian Federation.
  • Gustov Dmitriy Yu. - Moscow State University of Civil Engineering (National Research University) (MGSU) Candidate of Technical Sciences, Associate Professor, Associate Professor of Department of Construction Mechanization, Moscow State University of Civil Engineering (National Research University) (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation.

Pages 376-385

Introduction. Single-dipper hydraulic excavators are becoming widely used multifunctional machines. Upgrading the machine as a whole and its assemblies is an actual problem to be solved with the aim of reducing material consumption and increasing stability and throughput. The article presents results of computer simulation of the excavating part designed to reduce the weight of the equipment. These data can be used to improve the equipment of excavators when operating with non-standard excavating equipment of increased weight. Materials and methods. The excavating equipment of the Hitachi ZX270 excavator is taken as a prototype. Computer simulating and calculation of the excavating part is conducted using the T-FLEX software. The calculation is carried out for different modes of the excavator operation and for different orientations of the jig boom, dipper stick and dipper relative to each other: excavating with the entire width of the dipper, single-tooth excavating, swiveling the loaded excavator for unloading. The highest stresses arise in structural members in the considered calculation cases. The calculations are performed without accounting the oscillations occurring at transient operating modes and during locking. Results. The study determines a stress-deformed condition of the pseudotruss excavating part structures of the excavator with various lightened makes selected on the basis of computer simulation. Zones of the highest stresses and largest deformations are revealed as well as suggestions on their decrease are made. The research results are used to optimize the jig boom and dipper stick structures by the criterion of generated stress minimization. Conclusions. The obtained data and formulated recommendations are the basis for further detailed simulation of pseudotruss excavating part structures of excavators and other machines of various layouts and purposes.

DOI: 10.22227/1997-0935.2019.3.376-385

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