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ON FORECASTING THE LIFE OF FRICTION UNITS ACCORDING TO THE CRITERION OF APPROVED WEAR
Authors: V.V. IZMAILOV, Dr. Sc., L.E. AFANASIEVA, Cand. Sc., M.V. NOVOSELOVA, Cand. Sc.
Abstract: The article continues the publication of the results of the authors' research on the prediction of wear of parts with a hardness gradient along the depth of the material resulting from machining or the use of hardening techniques. To describe the change in the hardness of a material with distance from the friction surface, a more universal analytical dependence was obtained than in previous works of the authors. The previously proposed formulas are particular cases of this more general relationship. On the basis of the analytical dependence describing the change in hardness with depth of the material, the J. Archard equation known in tribology for estimating the amount of wear is extended to the case of surface wear with a hardness gradient in depth. A formula was also obtained for predicting the resource of a friction joint according to the criterion of acceptable wear. A specific example of resource estimation in the form of a friction path value, on which the limiting value of linear wear is reached, is given. It is shown that ignoring the hardness gradient when estimating the service life of friction joint can lead to a significant error.
Keywords: трение, изнашивание, упрочнение поверхности, градиент твердости, ресурс, прогнозирование
STUDY OF CHARACTERISTICS OF GALLIUM-CONTAINING MATERIALS FOR SLIDING ELECTRICAL CONTACTS WITH INTERMEDIATE LIQUID METALLIC MEDIUM
Authors: A.A. MITYUREV, Cand. Sc.
Abstract: A description is given of the designs of two installations for studying the electrical characteristics of liquid metals based on gallium and its eutectic alloys for liquid metal contacts (LMC) of electrical machines and apparatuses. The setups make it possible to determine the electrical resistivity of liquid metals, regardless of the design of liquid metal assemblies, without the formation of intermetallic compounds with gallium, in the temperature range according to GOST 8024-90 T = 30…180 °C. The linear nature of the temperature dependence of the electrical resistivity ρ = f(T) of gallium-containing materials for LMC has been experimentally confirmed. For this temperature dependence, the values of the coefficient ρ30 of the specific electrical resistance of LM at a temperature 30 °C and the temperature coefficient α of the electrical resistance of gallium and its eutectic alloys are determined: GI (77,5 % Ga / 22,5 % In); GIS (62 % Ga / 25 % In / 13 % Sn); GISZ (64 % Ga / 12 % In / 13 % Sn / 11 % Zn) used in modern high-ampere electric devices, including composite LMCs.
Keywords: sliding electrical contact, liquid metal contact, boundary friction, wear, gallium, eutectic alloy, electrical resistivity, temperature dependence
STRUCTURING PROCESSES IN LUMP PEAT PRODUCTION TECHNOLOGY
Authors: A.V. KUPOROVA, Senior Lecturer
Abstract: The lump peat and peat briquettes are the main types of molded solid peat fuel. The lump peat is mined in the field using solar energy for drying, and peat briquette is produced at the plant using artificial drying. The spontaneous process of forming a structure in lump peat is energetically beneficial. It is based on shrinkage deformations during drying, leading to a decrease in the size of the peat sample. At the same time, intermolecular interactions are strengthened and hydrogen bonds arise between the elements of the structure. In peat briquette intermolecular interaction is provided due to initial energy consumption for crushed peat pressing. The article discusses the main theories of structure formation. which make it possible to explain the complex physicochemical mechanism of these processes: the role of micro- and macrostructure; an energy approach; impact of the skeleton density of peat systems and a comprehensive assessment of the impact of mineral components. Recommendations are given on the application of these theories in technologies for the extraction of biogenic materials in the management of structure formation in peat and sapropel systems, as well as their compositions with mineral components.
Keywords: lump peat, peat briquette, molded fuel, structure formation, intermolecular interaction, hydrogen bond
ESTIMATION OF THE STRENGTH OF CUTTING ELEMENTS BASED ON THE ANALYSIS OF THEIR STRESS-STRAIN STATE
(USING THE EXAMPLE OF A MACHINE FOR MINING LUMP PEAT MTK-16)
Authors: K.V. FOMIN, Dr. Sc.
Abstract: In the process of operation, the cutters of working bodies of peat milling agents are subjected to significant loads, which leads to their deformation or destruction. It leads to increased power consumption, violation of technological requirements to the obtained products, reduction of productivity and reliability of the unit. Therefore, the evaluation of the strength of the cutting elements when performing a technological operation at the stage of designing is an actual task. The article presents a methodology of computer simulation of the stress-strain state of the cutting elements of peat milling units in order to assess their static strength at the design stage. The means of computer-aided design system KOMPAS-3D and the specialized design module APM FEM are used. A calculation example of the analysis of loading of knives of the machine for extracting molded lumpy peat MTK-16 is presented. The analysis of stress and strain state of cutting elements during interaction with wood inclusions is carried out. The influence of blunting of cutting edge of cutters on factors of safety margin of ultimate strength and fluidity is considered. The presented material can be useful in designing new and modernization of existing peat milling units in order to increase their reliability.
Keywords: peat milling unit, cutter, cutting element, finite element method, stress-strain state, strength
TO THE QUESTION OF THE DISTRIBUTION AND SCREENING OF GRAVEL ON THE SURFACE OF A THROUGH ROLL SIEVE
Authors: A.V. KONDRATYEV, Dr. Sc., S.M. KOCHKANYAN, Cand. Sc.,
T.I. LYSENKO, Senior Lecturer, A.A. GUSAROV, Assoc.
Abstract: The article presents the results of the movement and distribution of gravel grains, depending on their size, along the inclined surface of a trough-shaped roller sieve. The process of screening a fine fraction of gravel along the width of a chute with an auger intensifier has been studied. The parameters of the separating device have been obtained, which ensure the highest efficiency of stone material screening due to the rational distribution of material fractions over the roller sieve.
Keywords: trough-shaped roller screen, trough surface, elevation angle, stone size, screw intensifier, screw speed, disk speed, gravel grain distribution, material supply, screening efficiency
USE OF AVAILABLE INFORMATION TOOLS IN GEOLOGICAL ANALYSIS
Authors: T.B. YAKONOVSKAYA, Cand. Sc.
Abstract: The article describes the experience of using Excel analytical tools to analyze the results of a geological survey of a peat deposit. A technique for forming a bank of geological data in MS Excel is given, and the result of constructing stratigraphic columns and profiles of a peat deposit using graphic tools and a VBA macro used in MS Excel is described.
Keywords: peat deposit, geological analysis, stratigraphic column, profile, graphic toolkit, diagram, VBA, MS Excel
PREDICTIVE CONTROL OF THE QUALITY INDEX
OF THE GREEN TEA DRYING PROCESS
Authors: K.B. FAM, Postgraduate, P.M. MURASHEV, Postgraduate, V.N. BOGATIKOV, Dr. Sc.
Abstract: This paper describes the design, modeling and implementation of an automatic control system based on predictive control, taking into account the technological quality index for controlling air temperature and conveyor belt speed in a green tea dryer chamber with a fuzzy interaction between the surface temperature of the green tea layer and the moisture content of tea leaves. This automatic control system simulation was carried out using MatLab and Simulink. The results of numerical simulation show that the predictive control based on the technology quality index is stable and reliable in terms of suppression of input noise, and compared with the conventional multi-loop PID controller, the control system based on the technology quality index results in a significant improvement in the performance and control of the drying process.
Keywords: green tea drying, predictive control, automated control system simulation, conveyor belt dryer, technological quality index
MATHEMATICAL MODELING OF THERMAL AND HUMIDITY PROCESSES IN THE FOOD DRYING CHAMBER
Authors: A.V. KAYCHENOV1, Cand. Sc., V.V. ERESHCHENKO1, Senior Lecturer,
V.V. YATSENKO1, Cand. Sc., I.G. BLAGOVESHCHENSKY2, Dr. Sc.
Abstract: The article considers a mathematical model describing the dynamic properties of the drying chamber of a small-sized drying plant (UPOR-M) for the search for optimal technological regimes. The mathematical model determines the relationship between the temperature and moisture content of the supply air and the drying agent inside the dewatering chamber. The article also describes the experimental part of the research and the results of comparing theoretical and experimental data.
Keywords: drying chamber, mathematical model, dehydration process, experimental model
SCIENTIFIC SCHOOL OF ACADEMICIAN E.V. ZOLOTOV
AT THE CENTRAL RESEARCH INSTITUTE OF THE AEROSPACE FORCES OF THE MINISTRY OF DEFENSE OF RUSSIA: STAGES OF CREATION, ACHIEVEMENTS
Authors: M.L. TSURKOV, Cand. Sc., G.A. LOPIN, Dr. Sc.
Abstract: The article is devoted to the analysis of the main results of the scientific work of the full member of the Academy of Sciences of the USSR Evgeny Vasilyevich Zolotov. The period 1942–1967 is considered his formation and military service in the NII-2 MO, now the Central Research Institute of the Aerospace Forces of the Ministry of Defense of Russia. The work is dedicated to the 100th anniversary of the researcher's birth. His main theoretical developments as the first doctor of science at NII-2 MO, the features of the scientific school he created at the Institute are presented. An analysis is given of the proposed research methodology and the basics of building in Tver (Kalinin) a firing simulation complex for an experimental study of the vulnerability of air targets to the damaging effect of anti-aircraft guided air defense missiles with a proximity fuse. The research directions of Zolotov E.V., the main achievements and the level of their development at the present time.
Keywords: air targets, anti-aircraft guided missiles, scientific school, air defense, systems analysis, firing simulation system, vulnerability characteristics
MANAGEMENT OF MULTISTAGE MANUFACTURING BASED ON EVIDENCE THEORY AND METHODS OF INTERVAL ANALYSIS
Authors: B.V. PALYUKH, Dr. Sc., A.N. VETROV, Cand. Sc.
Abstract: The article is devoted to the analysis of the main scientific directions related to the activities of the full member of the USSR Academy of Sciences E.V. Zolotov during his work at the Kalinin Polytechnic Institute. The issues of guaranteed accounting of errors and noise distortions, measured and calculated technological variables are considered by applying the approach developed by E.V. Zolotov, based on the concept of variable zones proposed by him. This approach is currently implemented in the theory of artificial intelligence based on the mathematical apparatus of soft measurements and calculations. The principles of evolutionary management of multistage continuous production are substantiated on the basis of the Dempster – Schafer evidence theory and interval analysis methods. The combination of these approaches makes it possible to create a more efficient system of evolutionary control of multistage continuous production compared to traditional methods and reduce sensitivity to noise interference and delays in dynamic channels between the input and output of a continuous technological process. The proposed approaches are illustrated by setting specific tasks with solutions of control examples.
Keywords: evolution management, interval analysis, Dempster – Schaefer evidence theory
EVALUATION OF THE RANGE OF LASER RANGE FINDERS AS A PART OF OPTO-ELECTRONIC SYSTEMS IN LOCATION OF AERIAL OBJECTS
Authors: R.A. EGUZHOKOV, I.M. KHMAROV1, Cand. Sc., L.F. SHEVCHENKO, Cand. Sc.,
V.V. MESHKOV, Dr. Sc., G.N. MARKUSHIN
Abstract: The issues of testing laser rangefinders on open routes when locating air objects in the near and short-wave infrared wavelength ranges are considered. A method has been developed and tested that implements the processes of measuring and calibrating signals using aerostandards. The method is based on determining the effective scattering area of airborne objects, calculating the transmission coefficients of radar optical paths, experimental measurements of the maximum tracking distances of aerostandards by laser rangefinders, determining the angles of objects from their two-dimensional images, and calculating the ranges of rangefinders when locating typical airborne objects. The results of tests of two optical-electronic systems with laser rangefinders are presented. The ranges of action of laser rangefinders were evaluated in accordance with the specified requirements.
Keywords: laser range finder, effective scattering area, air object, field measurements, tests, range, aerostandard, multichannel optoelectronic system
OF HIGH-SPEED IMPACT OF FRAGMENTS ON A SYSTEM MODELING OF SPACED BARRIERS
Authors: O.Yu. FEDOSOV1, Cand. Sc., Yu.A. FEDOSOV2, Cand. Sc.
Abstract: The experimental-theoretical model «Model 1B» is presented, designed to calculate the main parameters characterizing the processes of penetration and destruction of spaced barriers made of various structural materials under the action of high-speed fragmentation elements. The principle of developing the «Model 1B» is to establish a system of equations and relations describing quantitative, qualitative and logical connections between the initial parameters and the results of high-speed interaction of fragments with a system of spaced barriers.
Keywords: secondary flow, high-speed impact, pulse, simulation, fragmentation element, barrier, energy