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Vibrations in engineering and technology

space SCIENTIFIC JOURNALS OF VINNITSA NATIONAL AGRARIAN UNIVERSITY

Issue №: 2(101)

Published: 2021.06.29
DOI: 10.37128/2306-8744-2021-2


Description:
The journal deals with the problems of vibration technologies and machines, mathematical methods of vibration process studies, information on design and technological development, presents teaching and methodological aspects of teaching in the Higher School of Applied Sciences, where vibration machines and technologies are studied.

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APPLICATION OF CURRENT LINES IN DETERMINING KINEMATIC CHARACTERISTICS IN STATIONARY PROCESSES OF PLASTIC FLOW OF METAL

DOI: 10.37128/2306-8744-2021-2-10
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Sivak Roman - Doctor of Technical Sciences, Associate Professor of the Department of General Technical Disciplines and Labor Protection of Vinnytsia National Agrarian University (3 Sonyachna St., Vinnytsia, Ukraine, 21008, e-mail: sivak_r_i@ukr.net) 

Нunko Iryna - Candidate of Technical Sciences, Associate Professor of the Department of General Technical Disciplines and Labor Protection of Vinnytsia National Agrarian University (3 Sonyachna St., Vinnytsia, 21008, Ukraine, e-mail: irynagunko@vsau.vin.ua). 

Zalizniak Roman - graduate student of the Department of General Technical Disciplines and Labor Protection of Vinnytsia National Agrarian University (3 Sonyachna St., Vinnytsia, Ukraine, 21008, e-mail: pacifistroma@gmail.com)  

 

 

Annotation

Methods of theoretical solution of problems in the processing of metals by pressure are insufficiently developed for practical use in the development and implementation of new technologies and improvement of existing ones. To meet the stringent requirements for the accuracy of determining the stress-strain state, it is necessary to have reliable information about the evolution of the development of the plastic deformation process at each point of the metal from the very beginning of the deformation. This will allow to obtain with high accuracy the important characteristics of the technological heredity of the products that they acquire as a result of their plastic processing. The first and important step in the calculations of the stress-strain state is to obtain the kinematic characteristics of the plastic flow of metal in the form of analytical dependences, which will formulate the patterns of deformation in the technological processes of metal forming.

The article considers the possibility of applying the method of current functions to determine the components of the strain rate tensor in established stationary processes of plastic deformation. It is assumed that in the case of axisymmetric plastic deformation of a metal in a channel with curvilinear boundaries, the kinematics of the process is similar to a plane flow. In obtaining the equations, the differential equation of current lines taking into account the incompressibility condition was used to determine the components of the strain rate tensor. To explain the physical meaning of the current functions, two infinitely close current lines were considered in the flow plane, and an expression was obtained for the flow through a finite transverse current tube. In the absence of radial velocity components at the boundaries, constraints are obtained that are imposed on derivatives of current functions at these boundaries. The developed method of calculating the kinematic characteristics of plastic deformation for established axisymmetric stationary processes will simplify the mathematical processing of the obtained results and increase the reliability of the determination of the stress-strain state.

 

Keywords: current lines, incompressibility condition, strain rate tensor, plane flow, stress-strain state, flow rate.

List of references

1. Rekechynskyi V. І. Zastosuvannia metody funktsiy toku v statsionarnyh protsessah plastychnogo deformuvannia. Vibratsii v tehnitsi і tehnologiah. Vinnytsia. 2020. №2 (97). S. 157-163.

2. Kurin M. А. Issledovanie metodom giperbol obtekania klina pri svobodnom rezanii. Metalofizika. Noveishie tehnologii. Fizika prochnosti i plastichnosti. Harkov. 2018. №7, т. 40. S. 859-876.

3. Ogorodnikov V. А., Derevenko I. А., Alieva L. I. Resurs plastichnosti metallov pri holodnom obemnom formoizmenenii: monografia. Vinnytsia: VNТU, 2016. - 176 s.

4. Beygelzimer Y., Reshetov A., Synkov S., Prokof’eva O., Kulagin R. Kinematics of metal flow during twist extrusion investigated with a new experimental method. Journal of materials processing technology. 2009. Vol. 209, issue 7. P. 3650-3656.

5. Ogorodnikov V. А., Derevenko I. A., Sivak R. I. On the Influence of Curvature of the Trajectories of Deformation of a Volume of the Material by Pressing on Its Plasticity Under the Conditions of Complex Loading. Materials Science.Vol. 54, 2018. P. 326-332.

6. Sivak R. Evaluation of metal plasticity and research of the mechanics of pressure treatment processes under complex loading. Eastern-European Journal of Enterprise Technologies. Kharkiv. 2017. №6/7 (90). P. 34-41.

 

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About journal

Topics of the journal:

The journal "Vibrations   in engineering  and technology" presents materials on the following issues

• Theory of processes and machines
• Mechanical Engineering and materialprocessing
• Processing and food production

Key information:
ISSN (print): 2306-8744
DOI: 10.37128/2306-8744

The certificateof massmediaState registration:kv no 16643-5115 from 30.04.2010 .
Founder of the journal: Vinnytsia National Agrarian University

Kind of publication: journal
Type of publication : Scientific
Publication status: Domestic
Year of founding:
Periodicity: 4 times a year
Extent: 18.75 nominal printed pages
ISSN: 2306-8744 (printed version), (online)
Language of edition  : (mixed languages) Ukrainian, English
The scope of the distribution and the category of readers: national, foreign, teaching staff, scientists, businessmen.
Periodical is included in the list of scientific professional editions of Ukraine approved by the Order of Ministry of Education and Sciences of Ukraine from 21.12.2015 No. 1328.
The journal "Vibrations in engineering and technology" is included in the "Catalogue of periodicals of Ukraine".
Journal subscription can be executed in each post office department.
 Subscription Index is  99720.

 

Old version of site: http://vibrojournal.vsau.edu.ua/

History of journal:

In June 1994 the 2nd International Scientific and Technical Conference "Application of vibrations for technological purposes" was organized on the basis of Vinnytsia State Agricultural Institute. Leading experts in this field, noting the significant contribution to the school of Vibration Engineering under the leadership of P. S. Bernyk, proposed to create a professional all-Ukrainian scientific and technical journal "Vibration in engineering and technology..The journal was foundedat Vinnytsia State Agricultural Institute and P.S. Bernyk was elected to be the chief editor .
For all these years (since 1994) theJournal "vibration in engineering and technology" published  94 issues wherestudy of vibration effects, the creation of progressive energy saving technologies and equipment for their implementation were highlighted.
Currently Kaletnik H.M  PhD , professor, academician NAAS is the chief editor of the "Vibrations in engineering  and Technology"
The journal "Vibration in Engineering and technology", which has no analogues on the territory of Ukraine, is well known abroad.