Application of a various model length for dynamic elastic ropes waves analysis of elastic ropes. I.

Autors
Chovnyuk Y. V., Ostapushchenko O. P., Kravchuk V. T., Kravchenko I. M.
Issue
Hoisting and transport equipment, 2021, №1(65)
Pages
17-30
DOI
10.15276/pidtt.1.65.2021.02
Abstract
In this work, a variable length rod model is used for dynamic analysis of elastic waveforms that occur in the ropes of cranes hoisting mechanisms during the lifting/lowering cargo process. It is necessary to study the wave fields in areas with moving boundaries and the reflection regularities impulses from such boundaries to solve such problems. Within the core model (rope model), such shock loading modes may occur, also a zone of plastic deformation occurs in the rods, which thus expands. In the first approximation of the wave elastic core part propagation, it is considered that the load applied to the elastic and plastic zones moving at a certain velocity is disregarded, without taking into account the processes in the plastic zone. Problems similar to the formulation for a domain with a moving boundary are studied in the thermal conductivity (Stefan problem), but the direct use of methods developed for parabolic-type equations in wave problems (which are usually described by hyperbolic equations in partial derivatives) is incorrect second-order derivatives are available in time. An approach based on the constructing solutions possibility of the wave equation from waves reflected from the fixed and moving semi-infinite area boundaries is proposed. The main elastic waves of rods/ropes characteristics that have circular cross section of variable area, so these rods are in the paraboloid cone rotation form. A comparative results analysis obtained in these rods with cylindrical type constant cross-section rods.
Keywords
model, rod, variable length, dynamic analysis, elastic waveforms, ropes, lifting mechanisms, cranes, load lifting/lowering.
Download article