Determination of design force factors in a multilayer winding of a rubber rope cable

Purpose. The main purpose of this study is to determine the design loads in the coils of a multilayer rubber-rope cable winding based on an improved method for calculating force factors, taking into account the absence of longitudinal compression of the rope in a multilayer winding and the dependence of the stiffness characteristics of the layers on the parameters of the multilayer winding. The methods. is based on the analysis of scientific works by leading specialists in the field of mechanical engineering specializing in the development of hoisting machines with a rubber-rope cable. Mathematical modeling methods were used to develop a model for determining the estimated force factors in a multilayer rubber-rope cable winding. Findings. Solving the problem of determining the force factors in a multilayer rubber-rope cable winding, the model of its spool body is represented as rings of finite thickness successively put on each other, while the cable tension does not change within the tape layer; between the cables of adjacent sections of the tape layers, the radial pressure in the rubber is constant; when the rings are put on, the values of displacements and stresses are summed up. The proposed method for calculating force factors includes components for determining the displacements of the layer of the rubber rope cable, the coefficients of transverse stiffness and expansion, and the approximating polynomials of the compression coefficients, loads, and deformations of the rope layers. The originality. For the first time, a structural-functional exponential model of the distribution of the reduced pressure in the coils of a multilayer rubber-rope cable windingis proposed, which takes into account the nonlinear decrease in contact loads from the center of the winding to the periphery. The model is described by an exponential dependence of the form and provides an approximation of experimental and analytical data with an error of less than 0.3%. This makes it possible to use it for fast and reliable engineering analysis of the stress-strain state of coils in multilayer rubber-rope cable winding. Practical implementation. The developed mathematical model for determining the design loads in the coils of a multilayer rubber-rope cable windingmakes 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.