Mehanika mašin, mehanizmov i materialov最新文献

{"title":"MINIMIZATION OF DEGRADATION OF RHEOLOGICAL AND TRIBOLOGICAL PROPERTIES OF HYDRAULIC FLUIDS IN FORCED MODES","authors":"Andrey V. PUZANOV, Sergey A. KURDUBANOV","doi":"10.46864/1995-0470-2023-3-64-17-24","DOIUrl":"https://doi.org/10.46864/1995-0470-2023-3-64-17-24","url":null,"abstract":"During operation of the drive, the working fluid is exposed to various physical factors of operational and functional nature. At the same time, fluids lose their properties, degrade. This leads to a decrease in productivity and an increase in wear of the movable parts of the hydraulic drive, a decrease in its service life. When forcing hydraulic drives according to power or speed parameters, the dynamics of these processes grows. The paper analyzes various factors that have a negative impact on the operational parameters of the working fluid of hydraulic drives. Software tools of multidisciplinary analysis of models of basic elements of hydraulic drives are used as research methods. The results of simulation of hydraulic drive operating processes are given. Zones and parameters of working fluid degradation degree dependence on external and internal factors are localized. The simulation results using the experiment data make it possible to assess the positive or negative contribution of certain design and technological solutions and operational modes to improvement of the rheological and tribotechnical characteristics of hydraulic drive fluids.","PeriodicalId":496597,"journal":{"name":"Mehanika mašin, mehanizmov i materialov","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134916950","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":"MECHANICAL AND MATHEMATICAL MODELS OF ONE TYPE OF BLOCK ELEMENTS FOR PROBLEMS OF UNDERGROUND GEOMECHANICS","authors":"Michael A. ZHURAVKOV, Mikhail A. NIKOLAITCHIK, Shiqi ZHANG","doi":"10.46864/1995-0470-2023-3-64-73-82","DOIUrl":"https://doi.org/10.46864/1995-0470-2023-3-64-73-82","url":null,"abstract":"The article presents a procedure for constructing mechanical and mathematical models to describe the stress-strain state of one type of block element, taking into account its own deformation. On the basis of this type of block element, it seems promising to build an implementation of the discrete element method for modeling the mechanical state of rock masses in areas of a clear violation of the continuity hypothesis. The introduced block element can be used both for issues under static loading and in the case of dynamic problems.","PeriodicalId":496597,"journal":{"name":"Mehanika mašin, mehanizmov i materialov","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134916043","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":"THERMODYNAMIC ANALYSIS OF THE FORMATION OF A NANOSTRUCTURAL POLYCRYSTALLINE MATERIAL BASED ON NANODIAMONDS MODIFIED WITH NON-DIAMOND CARBON (PART 1)","authors":"Vladimir T. SENYUT, Petr A. VITYAZ, Alexander M. PARNITSKY","doi":"10.46864/1995-0470-2023-3-64-60-65","DOIUrl":"https://doi.org/10.46864/1995-0470-2023-3-64-60-65","url":null,"abstract":"The influence of the size of carbon particles on the parameters of the graphite–diamond phase transformation is considered. It is shown that the surface energy of carbon nanoparticles of various shapes (spherical, columnar) makes a significant contribution to their total thermodynamic potential, which leads to a shift in the diamond–graphite equilibrium curve to the low pressure region and an expansion of the diamond phase stability region. At the same time, the change in the chemical potential (Gibbs free energy) during the direct (not catalytic) transition of thin-film graphite-like nanostructures into diamond will be higher than for “massive” graphite, which leads to an increase in the pressure of phase transformation into diamond. To reduce the parameters of diamond formation and obtain nanostructured diamond polycrystals, it is proposed to use nanodiamond particles with a nanometer surface layer of non-diamond (graphitelike) carbon as the starting material. In this case, the nanodiamond surface will influence the transition of a nanometer layer of graphite (graphite-like carbon) into diamond under more favorable thermodynamic parameters.","PeriodicalId":496597,"journal":{"name":"Mehanika mašin, mehanizmov i materialov","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134916361","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":"LOADS OF THE TELESCOPIC BOOM FROM LOCAL LOADS DURING TELESCOPING","authors":"Egor A. POTAKHOV","doi":"10.46864/1995-0470-2023-3-64-43-50","DOIUrl":"https://doi.org/10.46864/1995-0470-2023-3-64-43-50","url":null,"abstract":"One of the main factors affecting the performance of telescopic booms is the loss of local stability of the shelves and section walls. The loss of local stability of the sections occurs due to the development of plastic deformations in some of the most loaded sections of the telescopic booms or as a result of the loss of stable equilibrium of the sections even at the stage of elastic deformation. In this case, the maximum stresses of the telescopic boom are formed in the sections of the location of the supporting elements, where the summation of deformations from external loads and forces acting from the side of the supporting elements (local loads) occurs. The aim of the work is to study the loading of telescopic boom from the action of local forces in the process of telescoping. Analysis of the loading of telescopic boom in the process of extending (retracting) the sections is carried out using the example of the boom equipment of a railway crane Sokol 80.01M. Numerical modeling is used to study the local loading of telescopic boom of a crane during telescoping. Three telescoping modes are selected: consecutive extension (retraction) of sections without load; synchronous extension (retraction) of sections without load; consecutive extension (retraction) of sections with a load. The results of the virtual experiment for each mode are the time dependences of the local forces generated at the locations of the sliding bearings, and the time dependences of the vertical loads on the pins of the telescoping hydraulic cylinders. A comparison was made of the greatest loadings of the boom and telescoping hydraulic cylinders formed with three options for extending (retracting) sections. Based on the obtained dependencies of local loads, the maximum stresses of the telescopic boom were calculated during each telescoping mode.","PeriodicalId":496597,"journal":{"name":"Mehanika mašin, mehanizmov i materialov","volume":"198 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134916771","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":"MODELING OF THERMOELASTIC-VISCOPLASTIC DYNAMIC DEFORMATION OF FLEXIBLE CYLINDRICAL REINFORCED SHELLS","authors":"Andrei P. YANKOVSKII","doi":"10.46864/1995-0470-2023-3-64-25-36","DOIUrl":"https://doi.org/10.46864/1995-0470-2023-3-64-25-36","url":null,"abstract":"A mathematical model of thermoelastic-viscoplastic flexural dynamic deformation of thin circular cylindrical shells with complex reinforcement structures is developed. Weak resistance to transverse shear and wave processes in such composite structures are modeled in the framework of Ambartsumyan’s non-classical theory of bending. The geometric nonlinearity of the problem is taken into account in the Karman approximation. The composition materials are isotropic; their plastic deformation is described by the relations of the flow theory with a loading function that depends on temperature and strain rate. The connection between the thermal and mechanical components of the problem under consideration is taken into account. In the transverse direction of structures, the temperature is approximated by a 7th order polynomial. The formulated nonlinear two-dimensional initial-boundary value problem is numerically integrated using an explicit scheme of time steps. The elastic-viscoplastic and elastic-plastic dynamic behavior of fiberglass and metal-composite long cylindrical shells, which are orthogonally reinforced in the circumferential and longitudinal directions, is studied. Structures are loaded from the inside with pressure, which is similar to the pressure in an air blast wave. It is shown that flexible fiberglass shells during axisymmetric deformation can experience additional heating by 11…13 °C at certain points. Metal-composite structures similar in geometry and reinforcement structure — by 40…60 °C. Thermo-elastoplastic calculations lead to an overestimation of the maximum temperature values in fiberglass shells by 1.0…1.5 °C compared to thermoelastic-viscoplastic calculations, and for metal-composite structures, on the contrary, to an underestimation of these values by 20 °C. It is shown that the calculations of fiberglass shells can be carried out without taking into account the thermal response in them, and it is advisable to calculate the dynamics of metal-composite shells, taking into account the temperature response in them. The dynamic behavior of both metal-composite and fiberglass structures must be calculated taking into account the sensitivity of the plastic properties of their composition components to the strain rate.","PeriodicalId":496597,"journal":{"name":"Mehanika mašin, mehanizmov i materialov","volume":"198 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134916945","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":"STRUCTURAL MECHANISM OF PERFORMANCE LOSS OF COPPER COOLERS OF GLASS PRODUCTION WITH THERMAL DIFFUSION PROTECTIVE LAYER","authors":"Valery M. KONSTANTINOV, Ilya V. PLETENEV, Vladimir G. DASHKEVICH, Mitrofan A. SUDNIKOV","doi":"10.46864/1995-0470-2023-3-64-51-59","DOIUrl":"https://doi.org/10.46864/1995-0470-2023-3-64-51-59","url":null,"abstract":"A general assessment of options for increasing the resistance of elements of heat-removing devices made of copper is carried out. The peculiarity of high-temperature corrosion destruction of thermal diffusion aluminum- containing protective layer on M1 grade copper as the most common cause of loss of efficiency is studied. The proposed mechanism for the destruction of the thermal diffusion protective layer on the lamellar element of a cooler of glass production is shown, which is caused by two competing processes — layer “resorption” and structural changes during phase interaction. The mechanical destruction features of the protective layer are studied during pure bending and the formation of penetrating cracks deep into the product. The elastoplastic properties of the main structural components of the diffusion layer are studied by the nanoindentation method, and the values of their plasticity index are established.","PeriodicalId":496597,"journal":{"name":"Mehanika mašin, mehanizmov i materialov","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134916046","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 SPECIFICATIONS FOR MECHATRONIC CONTROL SYSTEMS FOR AUTOMATIC TRANSMISSIONS OF BATTERY ELECTRIC VEHICLES","authors":"Leonid G. KRASNEVSKIY, Sergey N. PODDUBKO, Alexander V. BELEVICH","doi":"10.46864/1995-0470-2023-3-64-5-16","DOIUrl":"https://doi.org/10.46864/1995-0470-2023-3-64-5-16","url":null,"abstract":"Battery electric vehicles with automatic transmissions are a new rapidly growing segment of electric vehicle and automatic transmission type configured for such applications. A promising direction of their development is integration of mechatronic control systems of automatic transmissions and electric drive, i.e. transition to integrated power units of battery electric vehicles. Pre-defined criteria are required to formulate the specifications for the design of the mechatronic control systems for such a unit. However, not only for mechatronic control systems, but also for battery electric vehicles with automatic transmissions themselves, sufficient experience in production and operation has not yet been accumulated, which determines the relevance of this article. Its purpose is to formulate approaches to the development of specifications on the emerging mechatronic control systems for automatic transmissions of integrated battery electric vehicles power units with automatic transmissions. The analysis (according to the formed information base) of the set of general requirements is carried out to the designs of close analogues — modern mechatronic control systems of automatic transmissions of hybrid electric vehicles, as well as the results of optimization of their parameters, characteristics and control algorithms of stage shifting processes of automatic transmissions for application in battery electric vehicles. It is shown that the compositions of basic functional properties of mechatronic control systems of automatic transmissions in battery and hybrid electric vehicles largely coincide. As a result, the composition of a set of basic criteria is formed for the evaluation of mechatronic control systems of battery electric vehicles. Based on the results of expert evaluation and analysis of analogues that meet modern requirements and are close to the types of domestic equipment, the basic specifications are proposed to the composition and functional characteristics of mechatronic control systems of automatic transmissions of power units of battery electric vehicles power (taking into account the private specifications to the subsystems included in them). The specification lists and their evaluation criteria include a number of established technologies in the global automotive industry. Taking into account that their practical application requires systematized information, which is difficult to find in the Russian-language presentation, the necessary explanations are given.","PeriodicalId":496597,"journal":{"name":"Mehanika mašin, mehanizmov i materialov","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134916951","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":"OPTIMIZATION OF CONCENTRATION OF ANTIOXIDANT ADDITIVE IN PLASTIC LUBRICANT BASED ON RAPESEED OIL","authors":"Feodor A. GRIGORIEV, Viktoriya V. PODGORNAYA, Larysa N. MARCHANKA, Inna N. KAVALIOVA","doi":"10.46864/1995-0470-2023-3-64-66-72","DOIUrl":"https://doi.org/10.46864/1995-0470-2023-3-64-66-72","url":null,"abstract":"Plastic lubricant with rapeseed oil dispersion medium is considered with addition of diphenylamine antioxidant additive. Analysis of tribotechnical, chemical and physicо-mechanical characteristics of the obtained lubricants with content of antioxidant additive from 0.5 to 10.0 wt.% is carried out. The effect of the additive concentration and temperature of introduction on the functional characteristics of lubricants is shown. A comprehensive method is proposed for evaluating the optimal concentration and temperature of the antioxidant additive introduction using an integral indicator, according to the lubricant total functional characteristics. It is noted that for plastic lubricant with a rapeseed oil dispersion medium and a dispersion phase based on a complex calcium thickener, the optimal temperature range for introducing an antioxidant additive is 85–95 °C at the cooling stage, at a concentration of 1.0 wt.%. In this case, the best combination of the finished product functional characteristics is achieved. Based on the proposed methodology and taking into account the experimental data, using expert criteria it is possible to optimize the concentration and temperature of introduction of antioxidant additive diphenylamine, to obtain a plastic lubricant with given characteristics.","PeriodicalId":496597,"journal":{"name":"Mehanika mašin, mehanizmov i materialov","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134916042","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":"STUDY OF THE STRESS-STRAIN STATE OF THE MATERIAL AT THE CRACK TIP, LOCATED IN THE AREA OF THE STRUCTURAL CONCENTRATOR","authors":"Daniil E. TULIN","doi":"10.46864/1995-0470-2023-3-64-37-42","DOIUrl":"https://doi.org/10.46864/1995-0470-2023-3-64-37-42","url":null,"abstract":"The influence of the stress concentrator is studied due to the design features of the welded metal structure of a loader crane on the stress-strain state of the material in the fracture process zone. Within the framework of the research, a physical criterion using the basic mechanical properties of the material is applied. A normal tear-off crack is considered under uniaxial loading conditions. FEM analysis of T-joint and lap welded joint models, as creating the highest stress concentration in metal structures of loader cranes, is carried out. A comparative analysis of calculation results for models with a crack in the concentrator area and models with a crack in a smooth plate is performed. The influence of the concentrator and its several parameters on the stress stiffness at the crack tip is shown. A general averaged estimation of the concentrator influence on the material stress state in the fracture process zone is proposed. Recommendations on taking into account the presence of the concentrator in analytical calculations are given.","PeriodicalId":496597,"journal":{"name":"Mehanika mašin, mehanizmov i materialov","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134916939","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}