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Item type:Наукова стаття, Mathematical Modeling and Experimental Analysis of the Thread Take-up Function in Single-thread Chain Stitch Sewing Machines Type 101(2026-03) Manoilenko, Oleksandr; Horobets, Vasyl; Puts, Vitalii; Volokh, Lyudmyla; Bezuhlyi, Dmytro; Bilashov, Konstantyn; Pleshko, SerhiyAn analytical and experimental methodology for evaluating functional characteristics of the single-thread chain stitch formation process (type 101) is proposed. The evaluation is based on degree of correspondence between the required and actual thread take-up, which reflects the machine’s efficiency and the quality of stitch formation. A measuring system and an experimental procedure were developed to record thread take-up under different material thicknesses and stitch lengths. The obtained dependencies were approximated by sixth-degree polynomials with high accuracy (R² > 0.99), which made it possible to construct mathematical models of the thread take-up process. For GK-9 type machines, excessive thread take-up (20–64% above the required value) was set up, causing uneven thread tension and reduced stitch stability. The proposed methodology ensures quantitative evaluation, prediction, and regulation of thread take-up process, which improves functional efficiency of sewing machines and supports development of adaptive thread take-up control systems.Item type:Наукова стаття, On the dynamics of vibrational capture of rotation of an unbalanced rotor(2022-05-16) Yaroshevich, Nikolay; Gursky, Volodymyr; Puts, Vitalii; Yaroshevych, Olha; Martyniuk, ViktorStationary (near stationary) rotation modes of an unbalanced rotor with the oscillation frequency of its axis are considered. From the standpoint of I. I. Blekhman vibrational mechanics, explanations of the mechanism of vibrational capture of the rotation of an unbalanced rotor are given. It is demonstrated that the vibration moment arising as a result of oscillations tends to synchronize vibrational and rotational movements. In addition its effect in the stationary mode becomes unambiguous – either braking or accelerating. It is shown that when a stationary rotation mode is established, large, relatively slow oscillations of rotor’s speed can occur. Theoretical results are confirmed by computer simulation.