Vibrations in engineering and technology

Kupchuk Ihor – Candidate of Technical Sciences, Associate professor, Associate Professor of the Department of Engineering Mechanics and Technological Processes in the Agricultural Industry, Faculty of Engineering and Technology, Vinnytsia National Agrarian University (3, Sonychna St., Vinnytsia, 21008, Ukraine, e-mail: kupchuk.igor@i.ua; http://orcid.org/0000-0002-2973-6914).

The article presents an integrated mechanico-rheological concept for describing the behavior of multicomponent feed materials in mixing apparatuses. The relevance of the study is driven by the fact that feed mixtures contain frictional, cohesive, fibrous, and pasty components, each characterized by specific deformation mechanisms that influence energy consumption and the dynamics of homogenization. Standard models applied separately to each material type do not adequately capture the spatial and temporal heterogeneity of stress–strain states within the working volume of mixers.

The study systematizes the physico-mechanical properties of feed materials and identifies four characteristic rheological states: frictional, cohesive, viscoplastic, and fibrous. For each of these, the applicability of the Mohr–Coulomb, Jenike, Herschel–Bulkley, and Bingham–Shvedov models is substantiated. It is demonstrated that, under the action of the mixing tool, the mixture develops local zones with different shear rates, consolidation levels, and structural stability, which determine the mosaic nature of the material’s rheological response.

Special attention is devoted to the energetic aspects of mixing. Relationships between shear stress, deformation rate, specific power dissipation, and the integral mixing energy required to achieve homogenization are established. The highest energy losses occur in cohesive and viscoplastic zones, where structural failure and intensive dissipation take place. Based on generalized effective rheological parameters, an approach for the quantitative assessment of mixing energy efficiency is formulated.

A formalized algorithm for the comprehensive application of mechanico-rheological models is proposed, incorporating parameter identification, kinematic modeling, calculation of local dissipation, and energetic integration. The algorithm enables prediction of the behavior of feed mixtures and selection of rational mixing regimes for various types of mixing equipment.

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