Scientific journal of the Ternopil national technical university最新文献

{"title":"Method of determination the initial elasticity modulus and timber deformation modulus under the influence of acid environment","authors":"S. Homon, O. Vereshko","doi":"10.33108/visnyk_tntu2022.01.029","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2022.01.029","url":null,"abstract":"The technique of experimental researches of timber by axial compression along fibers by short-term loading for operation in various acid environments (hydrochloric, acetic and lactic acids) during displacements increase is developed. The results of researches of the initial elasticity modulus and the deformations modulus taking into account the factor of environment aggressiveness are given. It is found that the effect of acids on wood with different impregnation periods significantly reduces the initial elasticity modulus and deformation modulus and depends on the impregnation period.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87865341","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":"Estimation of the load capacity and the strain-stress state of rod transporters","authors":"T. Dovbush, N. Khomyk, A. Dovbush, A. Palyukh","doi":"10.33108/visnyk_tntu2022.04.005","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2022.04.005","url":null,"abstract":"In the paper, an analytical study of the stress-strain state of the structural system of the rod conveyor of root harvesting machine with the maximum load arbitrarily distributed on the conveyor belt is performed. Rod conveyors are one of the main nodes for transporting and separating root crops through the technological channel of root harvesting machines, for loading them into a hopper and onto a vehicle. Structurally, they form an endless grid that surrounds the leading and driven sprockets or pulleys and supporting rollers. The entire structure of the conveyor is attached to the frame, which rests on the main frame of the harvesting unit. The shape and parameters of the rod conveyor are chosen depending on the layout of the unit and the required performance. Reasons for wear and failure of rod conveyors: deviation of the belt during operation, intensive wear of the holding elements in the places of their attachment to the traction elements and the traction elements themselves. It was found that the degree of wear of the left and right runs is different, as a confirmation of the unevenness of the load on the belt during operation. The uneven load of the conveyor is caused both by the transported pile of root crops and by the design features of the conveyor itself, in particular, uneven tension of runs, deviations during installation of shafts, installation of sprockets or pulleys, support rollers, etc. External loads acting on structural elements of agricultural machines are variable quantities. This should be taken into account when determining the stress-strain state of structures. It is possible to estimate the stress-strain state of complex structures of root-harvesting machines, their elements, and search for their optimal parameters, provided that the force factors in the sections of the elements are determined under full stress. In this way, it is possible to optimise the designs of such machines in terms of material consumption and work resource. The proposed method makes it possible to estimate the stress-strain state of rod conveyor elements according to operating conditions and the possible ways of their further improvement.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86453330","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":"Use of energy-efficient systems for ensuring the microclimate of the premises","authors":"H. Oliinyk","doi":"10.33108/visnyk_tntu2022.02.075","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2022.02.075","url":null,"abstract":"The article considers the use of the WLHP system, which is an alternative to already existing heating systems. It allows you to streamline engineering networks and implement energy-saving measures in the heat consumption sector. The advantages of the system are noted and the use of a heat pump in the system is recommended for the disposal of excess heat in the premises in order to reduce heat consumption. Measures related to energy-efficient technologies in Poland, Germany, and Sweden, including the use of heat pumps, were considered. The information regarding of the measurements СОР of energy-saving equipment implemented in Ukraine, in accordance with current standards, with the aim of improving the quality characteristics of the equipment present in the WLHP system, was introduced. The advantages of such a solution in comparison with traditional systems for ensuring the microclimate of premises are noted.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72679007","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 efficiency of using a heat pump in the heat supply system of a private house","authors":"H. Oliinyk","doi":"10.33108/visnyk_tntu2022.03.014","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2022.03.014","url":null,"abstract":"Currently, air-to-water heat pumps are in high demand, which, thanks to the high coefficient of heat conversion, reduce energy consumption and negative impact on the environment. The advantages of using a heat pump are safety, environmental friendliness, economy, and the fact that when using it, dependence on rising prices for natural energy sources is reduced. One of the main problems of the air-to-water heat pump is a decrease in productivity when the outside air temperature drops in winter. This paper analyzed the efficiency of air-to-water heat pump Mitsubishi Electric PUHZ-SHW230YKAR1 for providing a private house with heating, hot water supply and air conditioning. On the basis of the obtained results, graphs of the efficiency of the heat pump were constructed depending on the temperature of the environment and the coolant. The installation is able to generate heat at an external temperature of minus 28°C. The maximum heating temperature of the coolant is 60°C.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77670289","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":"Methodology and some results of studying the influence of frequency on functional properties of pseudoelastic SMA","authors":"V. Iasnii, N. Bykiv, O. Yasniy, V. Budz","doi":"10.33108/visnyk_tntu2022.03.045","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2022.03.045","url":null,"abstract":"The mechanical loading frequency affects the functional properties of shape memory alloys (SMA). Thus, it is necessary to study the effect of frequency in order to use successfully these materials in real structures. Based on the pseudoelastic cyclic behavior, the experimental methodology that allows testing of NiTi wires in stress controlled mode is proposed. Cyclic tensile tests are carried out using universal testing machine STM-100 at room temperature with loading frequencies of 0.1 Hz and 10 Hz. The functional dependencies are determined based on the experimentally obtained hysteresis loops. These functional dependencies comprise dissipated energy and damping factor. It iis found that the increase of loading frequency results in the worsening of functional properties, namely, to the decrease of dissipated energy and damping factor. This is caused by the fact that the regions of austenitic and martensitic transformation under the high loading frequency are absent. That is, the transformation of austenite into martensite does not occur, that stands for the pseudoelasticity effect. Nevertheless, it should be noted that the increase of loading frequency in 100 times augments the lifetime of pseudoelastic wire made of NiTi alloy roughly by 30%. It is determined that the increase of loading frequency results in the decrease of maximum strain in two times in the first loading cycle, and practically in 5 times after 200 cycles of loading.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79596558","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":"Website dependability evaluation model based on a multi-criteria approach","authors":"Grygoriy Hladiy, N. Khoma, Roman Zakaliak, Mariia Mohylska","doi":"10.33108/visnyk_tntu2022.03.105","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2022.03.105","url":null,"abstract":"The paper examines the existing approaches to defining the concept of website reliability and specifies the concept of a \"broad\" interpretation of its reliability as dependability. Five key criteria for evaluating website dependability were formed (availability, fault tolerance, recoverability, integrity, and confidentiality), which were used to build an evaluation model. This multi-criteria model is based on the modification of the \"best-worst method\" (BWM), by simplifying its algorithm as a result of refusing to choose the worst option. This makes it possible to reduce the number of pairwise comparisons in the evaluation of alternatives. A detailed algorithm of the proposed model was developed and its approval was carried out.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89183714","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":"Technology of autoclassification of changes in the process of multicomponent software development","authors":"A. Boichuk, S. Vashchyshak, T. Styslo, O. Pashkevych, Tetiana V. Boichuk, Vitalii Vashchynskyi","doi":"10.33108/visnyk_tntu2022.03.099","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2022.03.099","url":null,"abstract":"The paper proposes an automated method of classification of source code changes, which consists of two steps – clustering and comparison of clusters of classes. The currently existing methods of improving component software development are analyzed. Based on the analysis, it was established that the optimal method of increasing the productivity of the analysis of changes is the clustering of these changes. A method is proposed, according to which the distribution of changes by clusters is carried out automatically. Their comparison to classes is carried out by an expert. It is shown that the automation of the distribution of changes by clusters significantly reduces the time of examination of code changes, which makes it possible to use the obtained results to improve the quality of software during the development of complex software complexes. The results obtained in the course of the work provide an idea of possible data clustering algorithms with further analysis of the obtained set of clusters according to their parameters. Also, on the basis of the conducted research, the results of the comparison of the classifications of changes in the software system with open source code, performed using the proposed automated method and manually, are given. It is shown that the task of controlling changes that are undesirable at the current stage of development is solved significantly more effectively using the proposed method compared to a full examination of changes, as it allows identifying changes of classes prohibited at the current stage of development with less time spent. The application of the method in practice allows to improve the quality of the code due to the increase in the efficiency of the process of its examination. Using the approach proposed in the paper, the examination process under time constraints can be built more efficiently by selecting changes of the most important classes of changes. It has been proven that the method works perfectly if the same type of changes are analyzed, and when the changes combine heterogeneous code modifications, the quality of the automated classification deteriorates. The obtained results make it possible to extend the application of this method to other software complexes and systems, provided that differences in data types and their parameters are taken into account.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"PP 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84870849","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":"Adaptive pid regulation method of uninterruptible power supply battery charge current based on artificial neural network","authors":"A. Palamar, Mariia Stadnyk, Mariia Palamar","doi":"10.33108/visnyk_tntu2022.03.005","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2022.03.005","url":null,"abstract":"The paper considers the issue of improving the methods of uninterruptible power supply intelligent control based on adaptive algorithms with the use of artificial neural network technologies. An adaptive PID regulation method of the UPS battery charge current is proposed. A neural network based control scheme with adjustment of PID regulation coefficients has been developed. The simulation modeling was used to search for the artificial neural network topology, which would be the most effective according to the criteria of the battery charge current regulation accuracy. The use of artificial neural networks in the uninterruptible power supply control system made it possible to obtain more effective results for maintaining a stable battery charge current in the transient.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74581578","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":"Determination of tangential stresses in reinforced flexible wooden elements taking into account the nonlinearity of material deformation","authors":"P. Gomon","doi":"10.33108/visnyk_tntu2022.02.125","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2022.02.125","url":null,"abstract":"The basis for the calculation of reinforced bending wooden elements, taking into account the nonlinearity of wood deformation, has been developed. For the proposed calculation, optimized diagrams of wood deformation (polynomial of the 4th degree) were used. A method of determining the tangential stresses of bending reinforced wooden elements, taking into account the nonlinearity of the deformation of the material, has been developed.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80497594","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":"Analysis of the stress-strain state of the vehicle frame by finite element method","authors":"M. Stashkiv, I. Pidgurskyi, Oleh Pidluzhnyi, M. Pidgurskyi, Mykhaylo Levkovych, R. Skliarov, Andriy Mushak","doi":"10.33108/visnyk_tntu2022.04.089","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2022.04.089","url":null,"abstract":"Analysis of load-bearing structures of vehicles is carried out. The peculiarities of the operation of vehicles and their bearing systems are considered. It is noted that the loads acting on the structure are time-varying; their amplitude and frequency characteristics depend on the real load, the speed of the vehicle, the condition of the road surface and other factors. This can cause a high level of stress in the areas of structural and technological concentrators and result in the occurrence of fatigue cracks and frames destruction in these areas. The researching methods of operational loads and the stress-strain state of frame structures under static and dynamic loads are analyzed. It is noted that the finite element method is the most universal for the implementation of static, modal, harmonic and other types of analyzes of frame structures. The finite element method is used to investigate the stress-strain state of bearing structure of the 2PTS-2 trailer under different static load options. The full-scale CAD model of the trailer and its finite-element model are developed using specialized software SolidWorks. Calculations of the stress-strain state of the trailer frame are carried out for typical types of loads: straight-line movement, turning and lifting of the vehicles body with load. The analysis of the safety factors by stresses is carried out in order to take into account the uncertainties of the frame structure model and the uncertainties of the operational load. It is established that when considering the investigated options for loading of the frame structure, the most dangerous are those related to the unloading of the cargo, which requires further research into the specified processes.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"88 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80560286","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}