Onishchenko S. Justification of method of calculation of head rubber-cable ropes of mine hoists considering disturbed shaft geometry

Thesis for a scientific degree of Candidate of Technical Sciences on a special-ty 05.02.09 – dynamics and strength of machines. Dnipro University of Technol-ogy, Dnipro, 2021. The thesis is devoted to the solution of an acute scientific problem of in-creasing the level of operational safety of modern mine hoists with the head rub-ber-cable ropes on a basis of establishing the laws of formation and redistribution of a stress-strain state of head rubber-cable ropes during their interaction with mechanical system of a mine hoist considering the parameters of mine hoists and possible breakages of a cable base of ropes to justify the method of their calcula-tion. A study of influence of a cross-section shape of cables of a rubber-cable rope on compression and shear strength of the rubber matrix is performed. A discrete change in the number of rope cables with variable cross-section, the structure of rope cables made of twisted strands, mechanical characteristics of elastic shell material, and its shape are considered. The influence of the specified parameters on efficiency of a design of a hoist is estimated. A study of the stress-strain state of the hoisting rubber-cable rope due to displacement and rotation of the vessel in a horizontal plane of a shaft if per-formed. The influence of deviations of mine shafts on the stress-strain state of a rope and on the influence of vessel pressure on curved shaft guides are analyzed. The method of calculation of a stress-strain state of a hoisting rubber-cable rope considering influence of breakages of a cable base and a complex of factors is developed and justified. Analytical expressions are obtained in a general, closed form, which allows determining additional internal loads on rope cables, maximum values of stress concentration coefficients in rope cables, which are under the influence of external factors. The algorithm is justified, methodical rec-ommendations for establishing the stress-strain state of the rope caused by breakages of different cables in different cross-sections are developed and imple-mented. Recommendations allow determining the possibility of further operation of a hoist in mine shafts with disturbed geometry, including after accidents and technogenic disasters.