Dynamic Stability Of A Rope With Slow Variability Of The Parameters

Cao

et al. 2019

Shock and Vibration

Traction systems are a good choice for high-rise lift systems, especially in deep wells. With increasing lift depth and weight, rope-guided traction systems have become an essential design methodology in the mine lift field. In this paper, a comprehensive mathematical model is established to simulate the dynamical responses of a rope-guided traction system with different terminal tensions acting on the compensating rope. The results and analysis presented in this paper reveal dynamical responses in terms of longitudinal and transverse vibration. Additionally, a wide range of resonances occurs in the target system. Differences in the dynamical responses between a traditional traction system and tensioned traction system are analysed in detail. Through comparison and analysis, it is determined that terminal tension plays an important role in the suppression of longitudinal vibration in a system. However, changes in the amplitude of longitudinal vibration are independent of terminal tension, which only affects longitudinal elastic elongation and does not affect the basic shape of longitudinal and transverse vibrations. Based on this analysis, it can be concluded that longitudinal vibration suppression can be achieved by applying proper tension on the compensating rope to ensure that it reaches a tensioning state. Continuing to increase terminal tension is not beneficial for the vibration suppression of a system. The results presented in this paper will serve as a valuable guide for the design and optimisation of traction systems.

Section: Comparison Between Traditional Traction System and Tensionedmentioning

confidence: 99%

Modeling and Dynamic Behavior Analysis of Rope‐Guided Traction System with Terminal Tension Acting on Compensating Rope

Cao

et al. 2019

Shock and Vibration

2010 International Conference on Computing, Control and Industrial Engineering

“…The 6×19,6W(36) and triangular strand wire ropes have strongly torsional movement while suffering axial fluctuate load. Aiming at only extensional [1][2][3][4][5] , extensional-torsional coupled [6][7][8][9][10] , transverse [11][12] and extensional-transverse coupled [13][14] vibration investigation of hoisting system, a lot of literatures was proposed, but considering the extensionaltorsional-lateral coupled vibration and the influence of concentrated mass of the head sheave was studied little. Although, the hoisting conveyance is limited by rigid steel guide, the vibration behavior is complicated because of torsional movement, extensional and lateral excitation during drum winding.…”

Section: Introductionmentioning

confidence: 99%

Modeling and Natural Frequency Characteristics of Coupled Vibration with Varying Length of Hoisting Rope in Drum Winding System

Cao

Zhu

Peng

et al. 2010

In order to avoid resonance and enhance safety during designing hoist control method for mine hoisting system, the model of drum winding system guided by a head heave with varying length of hosting rope was established by the method of moving frame approach. According to Hamilton principle, the extensional, torsional and lateral coupled mathematical model with the effect of a concentrated mass was described to investigate the natural frequency characteristics. The mode shape and transcendental equation of angular frequency were obtained by supposing that the wave of vibration propagated with sine shape and using characteristic of the Heaviside function. By taking the scanning method of frequency and the hypothesis of transient, all vibration frequencies of the transcendental equation during drum winding could be calculated numerically, and frequencies at the bottom of shaft during the drum winding were given as a calculation example.

“…In these cases the rate of change of the length may often be considered as small over a time period corresponding to the fundamental natural frequency, and the respective system can be treated as a slowly varying non-stationary system [5]. The nonstationary, nonlinear behaviour of the ropes and cables in lift and hoist installations have been studied extensively [6][7][8][9][10][11][12][13]. However, a strong need exists to develop comprehensive models that account for the nonlinear couplings existing in the car -suspension rope installation.…”

Section: Introductionmentioning

confidence: 99%

Modelling, Simulation and Experimental Validation of Nonlinear Dynamic Interactions in an Aramid Rope System

Kaczmarczyk

Mirhadizadeh

2014

AMM

Vibration phenomena taking place in lifting and hoist installations may influence the dynamic performance of their components. For example, in an elevator system they may affect ride quality of a lift car. Lateral and longitudinal vibrations of suspension ropes and compensating cables may result in an adverse dynamic behaviour of the entire installation. Thus, there is a need to develop reliable mathematical and computer simulation models to predict the dynamic behaviour of suspension rope and compensating cable systems. The aim of this paper is to develop a model of an aramid suspension rope system in order to predict nonlinear modal interactions taking place in the installation. A laboratory model comprising an aramid suspension rope, a sheave/ pulley assembly and a rigid suspended mass has been studied. Experimental tests have been conducted to identify modal nonlinear couplings in the system. The dynamic behaviour of the model has been described by a set of nonlinear partial differential equations. The equations have been solved numerically. The numerical results have been validated by experimental tests. It has been shown that the nonlinear couplings may lead to adverse modal interactions in the system.