Issue №: 3 (134)
The journal presents the results of scientific research and addresses current issues in the development and improvement of agricultural equipment and technologies, particularly in the design, production, and operation of machines and technical systems in the agro-industrial complex, including aspects of their efficient functioning.
STUDY OF THE DYNAMIC CHARACTERISTICS OF A MULTIFUNCTIONAL ROTARY WORKING UNIT
Andrii BABII – Doctor of Technical Sciences, Professor, Head of the Department of Engineering Mechanics and Agricultural Machines, Ternopil Ivan Puluj National Technical University (56 Ruska St., Ternopil, 46001, Ukraine; e-mail: avbabiytntu@gmail.com; https://orcid.org/0000-0001-6198-0100)
Ivan VOVK – Postgraduate Student of the Department of Engineering Mechanics and Agricultural Machines, Ternopil Ivan Puluj National Technical University (56 Ruska St., Ternopil, 46001, Ukraine; e-mail: ivan_5479@ukr.net; https://orcid.org/0009-0000-5305-3550)
A mathematical model of the dynamics of a multifunctional rotary working unit was developed, and the influence of its structural and kinematic parameters on the critical shaft rotation speed and the amplitude-frequency characteristics was investigated. The working unit is considered as a complex mechanical system comprising an elastic shaft with discretely placed concentrated masses, as well as hinge-mounted flail hammers. The relevance of the study lies in establishing the characteristic rotation frequency zones under the condition of ensuring resonance-free operation of the rotor.
To construct the dynamic model, an energy-based approach and the Lagrange equations of the second kind were used. The model accounts for the energy of the shaft, the discretely placed masses, and the variable position of the flail hammers, as well as energy losses due to damping and the destruction of plant mass. As a result of the simulation, the equation of motion of the rotor was obtained, on the basis of which an expression was derived for determining the critical shaft rotation speed and the amplitude-frequency characteristic of the system.
A numerical experiment was conducted for an experimental rotor sample, which established that at an effective mass of 50.087 kg and a radial shaft stiffness of N/m, the critical rotation speed is 220.078 rad/s. The influences of effective mass, radial shaft stiffness, viscous damping coefficient, and imbalance magnitude on the position of the resonance zone and the oscillation amplitude were substantiated. It was established that an increase in the rotor's effective mass reduces the critical rotation speed, while an increase in shaft stiffness contributes to its growth. It is shown that an increase in damping significantly reduces the maximum oscillation amplitude in the resonance zone, whereas an increase in imbalance causes a proportional increase in vibrational loads.
Based on the simulation results, it was established that the working range of the rotor rotation frequency of 1200-1300 rpm lies in the pre-resonance zone and is characterized by insignificant oscillation amplitudes. The obtained value of the safety factor with respect to the critical frequency is 1.617, which indicates a sufficient distance of the operating mode from the resonance region.
1. Aljabr, A., & Flashner, H. (2025). Stability of steady-state solutions of Jeffcott rotor with varying rotational speed. Nonlinear Dynamics, 113, 7985–8001. https://doi.org/10.1007/s11071-024-10563-5 [in English].
2. Babii, A., & Vovk, I. (2025). Mathematical model of contact interaction between a rotating working body and plant stems for their shredding. Engineering, Energy, Transport AIC, 3(130), 99–106. https://doi.org/10.37128/2520-6168-2025-3-11 [in English].
3. Čedík, J., Chyba, J., Pexa, M., Petrásek, S., Jedelský, J., & Malý, M. (2018). Air flow conditions in workspace of mulcher. Agronomy Research, 16(3), 669–678. https://doi.org/10.15159/AR.18.127 [in English].
4. Crâştiu, I., Nyaguly, E., Deac, S., Gozman-Pop, C., Bârgău, A., & Bereteu, L. (2018). Determination of the critical bending speeds of a multy-rotor shaft from the vibration signal analysis. IOP Conference Series: Materials Science and Engineering, 294, 012035. https://doi.org/10.1088/1757-899X/294/1/012035 [in English].
5. Gao, Y., Yang, Y., Fu, S., Feng, K., Han, X., Hu, Y., Zhu, Q., & Wei, X. (2024). Analysis of vibration characteristics of tractor–rotary cultivator combination based on time domain and frequency domain. Agriculture, 14(7), 1139. https://doi.org/10.3390/agriculture14071139 [in English].
6. Kumar, A., & Sinha, S. (2025). Rotor dynamics: Modelling and analysis – A review. Journal of The Institution of Engineers (India): Series C, 106, 463–476. https://doi.org/10.1007/s40032-024-01135-y [in English].
7. Pei, D., Ye, Z., Pi, X., & Zhang, T. (2024). Research on the critical speed of a double span rotor system based on finite element method. Journal of Physics: Conference Series, 2840, 012036. https://doi.org/10.1088/1742-6596/2840/1/012036 [in English].
8. Šavrnoch, Z., Sapieta, M., Dekýš, V., Ferfecki, P., Zapoměl, J., Sapietová, A., Molčan, M., & Fusek, M. (2024). Probabilistic analysis of critical speed values of a rotating machine as a function of the change of dynamic parameters. Sensors, 24(13), 4349. https://doi.org/10.3390/s24134349 [in English].
9. Babii, A., Vovk, I., & Hlado, Yu. (2025). Bahatofunktsionalnyi rotatsiinyi robochyi orhan [Multifunctional rotary working element]. In Innovatsii v ahropromyslovomu kompleksi, mashynobuduvanni ta transporti [Innovations in the agro-industrial complex, mechanical engineering, and transport]: Proceedings of the International Scientific and Practical Conference (pp. 6–8). NUWEE. [in Ukrainian].
10. Babii, A., & Vovk, I. (2026). Doslidzhennia enerhetychnykh pokaznykiv pry podribnenni roslyn bylnymy robochymy orhanamy [Research of energy parameters in plant shredding using flail working bodies]. Central Ukrainian Scientific Bulletin. Technical Sciences, 14(45), 77–86. https://doi.org/10.32515/2664-262X.2026.14(45).77-86 [in Ukrainian].
11. Babii, A. V., Vovk, I. V., Hlado, Yu. B., & Valiashek, V. B. (2025). Rotatsiinyi robochyi orhan [Rotary working body] (Ukraine Utility Model Patent № 160845). Ukrainian National Office for Intellectual Property and Innovations. [in Ukrainian].
12. Volskyi, V. A., & Kotsiubanskyi, R. V. (2023). Konstruktsiino-tekhnolohichni osoblyvosti suchasnykh kombinovanykh znariad dlia podribnennia roslynnykh reshtok odnochasno z obrobitkom gruntu ta perspektyvy yikh rozvytku [Design and technological features of modern combined implements for shredding plant residues simultaneously with soil tillage and prospects for their development]. Mechanics and Automation of Agro-Industrial Production, 2(116), 16–24. https://doi.org/10.37204/2786-7765-2023-2-2 [in Ukrainian].
About the journal
G8 – Materials Science
G9 – Applied Mechanics
G10 – Metallurgy
G11 – Mechanical Engineering (by specializations)
The journal "Engineering, Energy, Transport AIC" is indexed according to the following databases and catalogs:
The All-Ukrainian scientific journal “Technology, energy, agriculture transport AIC” is an open-access scientific publication that publishes the results of original research, theoretical and applied developments, as well as scientific papers in the fields of engineering sciences, energy systems, and transport technologies of the agro-industrial complex.
The main objective of the scientific journal “Technology, energy, agriculture transport AIC” is to disseminate the results of modern scientific research and to promote the development of technical, energy, and transport solutions for the agro-industrial complex through the publication of scientific materials characterized by scientific novelty and practical significance in the field of design and modernization of machinery, equipment, and technologies.
The journal’s activities are focused on supporting the development of engineering science, stimulating the implementation of innovative approaches into industrial practice, as well as ensuring effective exchange of scientific achievements among researchers, educators, engineers, and other specialists in relevant fields.
Objectives of the Journal
To achieve its defined objective, the journal ensures the implementation of the following key tasks:
· publication of the results of fundamental and applied research covering the fields of applied mechanics, mechanical engineering, materials science, energy systems, electrical engineering, electromechanics, and transport systems of the agro-industrial sector;
· promotion of the implementation of advanced technical and technological developments aimed at improving the efficiency of machinery, equipment, and production processes;
· creation of conditions for active scientific exchange among research institutions, higher education institutions, industrial enterprises, and other interested organizations;
· support for the development of interdisciplinary research and expansion of cooperation among specialists in various fields of science and technology;
· promotion of the improvement of the scientific and technical level of research related to the design, modernization, and operation of technical equipment used in agro-industrial production;
· dissemination of information on modern achievements in science and technology and the implementation of innovative technologies in the fields of technical support, energy, and transport;
· development of a scientific information environment that facilitates effective scientific communication and the integration of national research into the international scientific community.
Publication frequency: 4 issues per year
Languages of publication: Ukrainian, English
Editor-in-Chief: Vitalii YAROPUD
State Registration: Decision of the National Council of Ukraine on Television and Radio Broadcasting № 1337 and № 1180. Media Identifier: R30-05173
EDRPOU Code: 00497236
Publisher ROR: https://ror.org/05m3ysc06
Publisher DOI prefix: 10.37128 ISSN (print): 2520-6168
The scientific journal is included in Category “B” of the List of Scientific Professional Publications of Ukraine in which the results of dissertation research for obtaining the degrees of Doctor and Candidate of Sciences may be published in the following specialties: G8 – Materials Science; G9 – Applied Mechanics; G10 – Metallurgy; G11 – Mechanical Engineering (by specializations). (Order of the Ministry of Education and Science of Ukraine dated June 11, 2026 №928
Technology, energy, agriculture transport AIC is a scholarly professional journal with a long-standing history and stable academic tradition, reflecting the evolution of engineering and technical sciences within the agro-industrial sector of Ukraine.
The journal was founded in 1997 under the title Bulletin of Vinnytsia State Agricultural Institute. According to the Resolution of the Presidium of the Higher Attestation Commission of Ukraine dated September 11, 1997, the publication obtained the status of a professional scientific journal, which enabled the publication of the main results of doctoral and candidate dissertations in technical sciences. From its inception, the journal positioned itself as an academic platform for addressing current issues of mechanization, electrification, and technical support of agricultural production. During 2001–2014, the journal was published under the title Proceedings of Vinnytsia National Agrarian University. Series: Technical Sciences (State Registration Certificate of Print Media KV No. 16644-5116 PR dated April 30, 2010). Throughout this period, a systematic approach to the selection and peer review of scientific manuscripts was established, the thematic scope of publications was expanded, and continuity of scientific directions as well as the development of sectoral engineering schools was ensured. Since 2015, the journal has been published under its current title, Technology, energy, agriculture transport AIC (State Registration Certificate No. 21906-11806 R dated March 12, 2016). The change of title reflected the expansion of the journal’s thematic coverage and its orientation toward interdisciplinary research in mechanical engineering, energy systems, electrical engineering, transport technologies, automation, and digital solutions for the agro-industrial complex.
