Simulation of the cable part of the load-lifting device drive, represented as a rod system

Abstract

In this paper, the cable part of a lifting device operating on a marine vessel was studied. When the object is being towed, the “the vessel – the lifting device – the cargo system” makes non-stationary motion. In this case, the parameters of the cable part of the device: the distance between the points of the wire cable hanging, the length of the wire cable, its shape, and hydrodynamic resistance are variable. In the simulation of wire rope, it is proposed to replace it in the form of a rod system. During researches the mathematical model of small fluctuations of rod system on the basis of the Lagrange equation of II sort has been developed. Using the example of two-, three- and four-rod systems from age-old equations, dependences for their own frequencies are obtained and natural forms of small vibrations are constructed. However, as the number of rods in the system increases, the number of elements and degrees of freedom increases, leading to a significant complication. Therefore, at modeling similar types of load-lifting elements, it is recommended to limit the number of rods.