Scientific journal of the Ternopil national technical university最新文献

{"title":"Modern strategies for repairing transport systems and facilities using modified epoxy plastics","authors":"Andrii Buketov, K. Klevtsov, O. Sapronov, O. Sharko, Roman Nehrutsa","doi":"10.33108/visnyk_tntu2023.02.111","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2023.02.111","url":null,"abstract":"The important feature of the ship transportation systems and facilities operation is the possibility of using methods of current and capital repair of machines and mechanisms. The durability of machine parts and elementsoperation significantly depends on the state of the mechanisms at the current moment, the critical conditions of their thermal and power load. This applies especially to engine room components of modern vessels. Based on the above-mentioned problem, the solution of the issue of current repair of transport systems and facilities is important today, since the occurrence of emergency condition while the systems are in operation requires their immediate leveling during the vessels voyage. In this context, the application of modern strategies for the repairing of transport systems and facilities, which involve the use of modified polymer epoxy plastics, is promising. The development of new materials with improved properties is impossible without scientific research of their cohesive characteristics. The latter can be improved by introducing chemically active modifiers into epoxy oligomer. The optimal content of the modifier in the epoxy oligomer was determined in this paper according to the cohesive strength criteria, such as destructive stresses and flexural elastic modulus, impact strength of composites. Epoxy oligomer ED-20 was chosen as the basis for binder formation. Compositions were polymerized with PEPA hardener. 2.4-diaminoazobenzene-4’-carboxylic acid was used as a modifier. It is proved that for the formation of materials with improved cohesive properties, it is necessary to use the composition of the following content: epoxy oligomer ED-20 (100 wt. parts), hardener PEPA (10 wt. parts), modifier 2.4-diaminoazobenzene-4’-carbonate acid (0.5... 1.0 wt. parts). The formation of such material ensures significant increase in the mechanical properties of composites compared to the original epoxy matrix. An important scientific and technical problem regarding the improvement of modern strategies for transport systems and facilities repairing by means of new modified epoxy plastics is solved in this paper. This is achieved by selecting the structural component materials based on the results of the investigations of interphase interaction processes during the formation of heterogeneous systems and their cohesive properties.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"118 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88987950","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":"Establishing the causes of premature damage of steam turbine rotor blades of TPP","authors":"P. Solovei, O. Student, L. Svirska, I. Kurnat, S. Krechkovska, Taras Gural","doi":"10.33108/visnyk_tntu2023.02.046","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2023.02.046","url":null,"abstract":"The technical condition of the metal of the steam turbine blade was analyzed and the reasons for its fracture were established. It was shown that the relative elongation δ of the blade metal varied from 7.4 to 11.5%, and was lower than the regulated level. The low values of δ and the obtained values of the ratio between yield strength and ultimate tensile strength σYS / σUTS, which varied from 0.8 to 0.89, indicate a low margin of plasticity of the blade metal, which contributed to its cracking under the action of working loads. Metallographic analysis revealed pores in the surface-hardened layer of the blade. They caused low adhesion of the layer with the base metal of the blade, and also of crack initiation. The high stress concentration and the contact of the blade metal with the working medium contributed to the growth of a subcritical corrosion-fatigue crack in the cross-section up to its complete destruction.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"72 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90358171","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":"The methodical peculiarities of the investigation of portal crane rolled steels degradation","authors":"O. Nesterov","doi":"10.33108/visnyk_tntu2023.01.066","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2023.01.066","url":null,"abstract":"Rolled structural steels of port structures, operating under intensive cyclic loading, are particularly susceptible to the degradation of their mechanical properties. Advantages of the investigation of operational degradation of steels based not on fatigue strength characteristics, but on characteristics of resistance to brittle fracture using the example of determining the impact strength of longitudinal and transverse Charpy samples in relation to the rolling direction of sheet metal for 10 local areas at different structural nodes of portal crane are analyzed. This is caused to a great extend by micro-layering along the stretched fibers in the rolling direction of the rolled product. Accordingly, the mechanical properties of the metal become particularly sensitive to the direction of samples cutting in relation to the direction of rolling. Therefore, in order to evaluate the steel operational degradation it is recommended to use transverse samples in which the direction of micro-laayering coincides with the direction of rolling. Possible role of the marine environment in enhancing the degradation of steel due to its flooding properties is also considered in this paper.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82522918","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":"Very-large-scale integration device for parallel vertical group computing the sum of squared differences","authors":"I. Tsmots, Ihor Ihnatiev, S. Ivasiev","doi":"10.33108/visnyk_tntu2023.02.005","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2023.02.005","url":null,"abstract":"Is a paper that proposes a new method for computing sum-of-squares differences in a parallel vertical environment. The method is based on a group approach, which allows you to divide the task into several subtasks and calculate them in parallel. The article considers the problem of calculating the sum of squared differences between elements of large data arrays. Applying traditional methods of calculating such sums in parallel environments can be inefficient due to the exchange of large amounts of data between nodes. The proposed method allows to reduce the amount of transmitted data and increase the efficiency of calculations. The article proposes a new method for calculating the sum of squared differences, which allows to increase the efficiency of calculations in a parallel vertical environment. Testing of the method on different data sets shows its high efficiency compared to traditional methods of calculating sums of squared differences in parallel environments. The proposed method can be applied in various areas that require the processing of large volumes of data, and allows to increase the efficiency of calculations and reduce their execution time. The methods, algorithms and structures of devices for computing the sum of squared differences have been analyzed and their defects have been defined in the article. It has been defined that the device for computing the sum of squared differences should support the next: high device utilization; the use of capabilities and benefits of VLSI; short-term development and moderate price. The development of the device has been suggested by computing the sum of squared differences using modularity principles, coordination between data flow and computing capability of the device, pipelining and space parallelism, localization and simplification of links with elements. The proposed method can be useful for researchers in the fields of parallel computing and data processing, and can find applications in various fields such as data science, machine learning, image processing, and bioinformatics.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"68 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75941925","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 relational database management systems performance evaluation during computer systems design","authors":"V.V. Yatsyshyn, O. Pastukh, A. Palamar, Ruslan Zharovskyi","doi":"10.33108/visnyk_tntu2023.01.054","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2023.01.054","url":null,"abstract":"Based on the recommendations of the international standard ISO 25010, a formalized technology for evaluating the performance of relational database management systems in the design of computer systems has been developed. Attributes and metrics of the performance characteristics were defined and elementary functions for evaluating the quality of their implementation were developed. The procedures for planning and performing evaluation processes are substantiated, which makes it possible to quantitatively express the quality of both an individual attribute and their aggregate in the form of sub-characteristics and characteristics of the external quality model. The proposed technology provides flexibility and formalizes the process of choosing the best DBMS alternatives, taking into account the type and requirements of a specific designed computer system.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78706148","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 of analytical research of the microclimate of the bus drivers cab using the ANSYS-FLUENT software environment","authors":"Y. Voichyshyn, K. Holenko, Orest Horbay, V. Honchar","doi":"10.33108/visnyk_tntu2023.01.090","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2023.01.090","url":null,"abstract":"The article analyzes the current state of microclimate problems in vehicle cabins, studied in the world and in Ukraine. An analysis of the scientific research of some scientists working in this field is carried out, as well as the state of regulatory documentation, both abroad and in Ukraine. With the help of mathematical dependencies, a description of the theory of air mass transfer is provided. Calculations of air flows in the front part of the bus cabin, in particular in the driver's working area, were carried out using the ANSYS-Fluent software environment.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"2014 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73449870","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 the characteristic function of discrete-time conditional linear random process and its application","authors":"M. Fryz, Bogdana Mlynko","doi":"10.33108/visnyk_tntu2023.01.016","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2023.01.016","url":null,"abstract":"The discrete-time conditional linear random process is defined, and its properties in the context of application for mathematical modelling of information signals in energy and medicine are analyzed. The relation to the continuous-time counterpart is considered on the basis of time sampling and aggregation. One-dimensional and multidimensional characteristic functions of discrete-time conditional linear random process are obtained using conditional characteristic function approach. The conditions for the investigated model to be strict sense stationary are justified.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76113453","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":"The concept of improvement high-strength aluminum alloys FSW joint properties via post-weld explosive treatment","authors":"R. Kosturek","doi":"10.33108/visnyk_tntu2022.03.125","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2022.03.125","url":null,"abstract":"The study describes the theoretical background and technological aspects of the post-weld explosive treatment of high-strength aluminum alloy FSW joints. Although FSW allows to effective join high-strength aluminum alloys, the heat generated during the process causes undesirable changes in the strengthening phase, giving a joint efficiency of about 80%. The load-carrying capabilities of these joints can be increased via post-weld treatment (e.g. shot peening, laser shock peening). The new, potential post-weld treatment that is presented in this paper is based on the affection of the welded joint by a shock wave generated during the detonation of explosive material. Such post-weld explosive treatment would result in the hardening of the low-hardness zone, which often determines the mechanical properties of precipitation-hardened aluminum alloy FSW joints. Studies show that explosive welding of annealed aluminum alloys increases their microhardness by about 25% as the result of a high-velocity collision. If a similar effect can be achieved in explosive hardening, the microhardness of the low-hardness zone will increase entailing an improvement of entire joint mechanical properties. The variety of explosives materials used in metalworking (covering the values of detonation velocity from about 2000 m/s to 8000 m/s) and different systems for shock-wave affection gives many technological possibilities. In this work are discussed two different explosive hardening systems: with direct placement of explosive material on a treated welded plate and with an additional driven plate, which provides a higher pressure impulse. Considering that affecting of high amplitude shock wave introduces defects into the structure and decreases residual stresses in the welded joints, the application of an appropriate technological system creates a potential for improving the load-carrying capacities of discussed joints, especially in a condition of cyclic loading.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"172 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74853742","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":"Wear resistance of working bodies of ground treatment machines strengthened by composite electrolytic coatings","authors":"Myroslav Stechshyn, Andriy Martynyuk, Yu. S. Bilyk, V. Lyukhovets’","doi":"10.33108/visnyk_tntu2022.01.040","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2022.01.040","url":null,"abstract":"The results of researches of influence of composite electrolytic coverings (CEP) on abrasive wear resistance of working bodies of tillage machines: paws of cultivators, disk harrows, plowshares are resulted in work. The influence of SiC (silicon carbide) filler particle sizes and their volume content in the nickel matrix on the tribological characteristics of QES applied to steel samples 45 was studied. QES with inclusions of silicon carbide fractions 28/20 and 50/40 microns, which have the least wear at all loads. The content of filler in such coatings is, respectively, 24 and 28 vol.%. Compared with galvanic nickel, such coatings have a reduction in wear of 13 and 5 times at loads of 20, 40, 60 N, respectively. Analysis of the test results showed that with increasing load, such as the coefficient of friction decreases and with increasing SiC particle size for the range of particle sizes of the filler 40… 60 μm, the coefficient of friction is minimal. For coatings with large filler particles (fraction 100/80) the coefficient of friction is higher. Thus, tribological studies show the prospects and effectiveness of CEP to increase the wear resistance of the working bodies of tillage machines.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81298222","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":"A one-dimensional mathematical model of piezoelectric transformers for cad system","authors":"Volodymyr Medvid, I. Belyakova, O. Maruschak, Vadim Piscio","doi":"10.33108/visnyk_tntu2022.04.102","DOIUrl":"https://doi.org/10.33108/visnyk_tntu2022.04.102","url":null,"abstract":"The model of a piezoelectric transformer (PT), which is more convenient for modeling in comparison with those, which are widely used in practice, is presented in this paper. Moreover, the proposed model can be directly applied in developing radio-electronic equipment and integrated into computer-aided design systems (CAD). The given model of piezoelectric transformer considers not only one but several harmonics and is simple for interactive change of parameters in the modeling process, as well as takes into account and changes the parameters of piezoelectric devices without leaving the basic CAD of radio-electronic equipment. The implementation of this model in the MicroCAP computer-aided design system is shown in the example. The results obtained during modeling are compared with experimental data.","PeriodicalId":21595,"journal":{"name":"Scientific journal of the Ternopil national technical university","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83482436","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}