Analysis of torsional properties of a rubber rope as a composite material in multilayer winding

Abstract

Purpose. The main purpose of this study is to analyse the results of a theoretical study on the effect of the longitudinal stiffness of the rope on the mechanism of deformation of the winding body as a composite material on the basis of experimental data. The methods. The methodology is based on the analysis of scientific papers by leading experts in the field of mechanical engineering specialising in the development of hoisting machines with rubber-rope cables. The development of the model of torsional stiffness of the winding body of reel hoists was based on mathematical and physical modelling methods, including methods of planning a multifactorial experiment and statistical processing of experimental data. Findings. When solving the problem of determining the stiffness of the body of a rubber-rope winding, the physical model of its spool body was presented in the form of a rubber-metal hinge. After processing the results of the experiment to determine the parameters of the winding body, an analytical expression was obtained to calculate the torsional stiffness of the winding body of a rubber-rope cable. The originality. The regularities of the influence of the parameters of a rubber rope on the torsional stiffness of its winding body have been established. The stiffness of the winding body depends on its outer diameter quadratically, while the local stiffness is weak. With a small number of turns, the stiffness of the homogeneous body exceeds the local stiffness, but the total pliability is low. The risk of dynamic effects in a spool hoist during braking increases with a large number of turns, when the homogeneous body stiffness is much lower than the local stiffness. The total torsional stiffness of the winding body can be determined by the proposed formula with sufficient accuracy for dynamic analysis. Practical implementation. The developed mathematical model for determining the torsional stiffness of a rubber rope winding makes it possible to find such values of the parameters of a spool hoist that will avoid the danger of dynamic effects during emergency and operational braking of the device caused by the torsional stiffness of the winding body.