RESEARCH OF STRESS-STRAIN STATE OF ORE GRINDING MILLS

Over the past decades, computing complexes based on finite element methods, such as "MARS," "Lira," "ASKA," "ADINA," "COSMOS," "ANSYS," etc., have been developed and are now successfully operational. However, alongside the development of powerful universal computing packages for various applications, there is a growing trend towards specialized complexes tailored to solve specific practical problems. This trend is driven by the advancement of automation systems for designing both typical structures and computer codes. In this paper, we address the problem of determining displacements and stresses in ore-grinding mills under asymmetric loading, based on a developed methodology and a specialized program for calculating the shells of revolution. Ore-grinding mills are complex structures resembling stacked branched shells of revolution supported by fins. The methods for calculating such structures, considering meridian edges, in accordance with the theory of constructive-orthotropic shells, are well-developed. While the calculation schemes of general-purpose program packages account for the self-weight of the drum, the weight of the ball loading, and the reaction of the supports, our specialized program additionally considers centrifugal forces of the drum, pulp, and inwall. It also accounts for the branching of the drum meridian and the possibility of the tip resting on one or two bearings, positioned at an angle φ in the tip section. These structures are loaded with their own weight, the weight of the inwall in the form of armored plates, as well as the weight of the ore, which, when mixed with water, is crushed by metal layers or rods located in a cylindrical drum. The crushing of ore occurs due to the rotation of the structure, which is horizontally positioned and supported by sliding bearings. This necessitates accounting for the centrifugal forces of the specified masses, as well as reactions from the bearings. Detailed description of load calculation and their representation by Fourier series is provided, along with a comprehensive consideration of taking rigid shifts into account when calculating the structural strength. The results of the study on the stress-strain state and strength of ore grinding mills are presented comprehensively.