Elevator Rope Research Articles

Study on analysis of elevator rope free vibration test with elemental test

Study on analysis of elevator rope free vibration test with elemental test

Method of estimating the lateral vibration of an elevator rope from the vertical vibration of a compensating sheave

ABSTRACT Observing the vibration of the elevator ropes in an elevator shaft is a difficult task. Although several methods of observing the displacement using image processing or laser displacement meters and then estimating the vibration through an observer or a Kalman filter have been developed, it is difficult to install sensors because of the movement of the elevator car and the thinness of the rope as an observation target. Therefore, in this study, we focus on a pulley called a compensating sheave that does not change its lateral position as the car and ropes move. The horizontal vibration of the ropes causes the compensating sheave to vibrate in the vertical direction. A method of estimating the horizontal vibration from this vertical vibration using arc length calculations and a short-time fast Fourier transform is proposed. First, the vertical vibration of the compensating sheave is distributed to the various mode responses based on the predominant frequency of the vertical vibration. The mode-decomposed vertical vibration is then converted into a horizontal mode response using an arc length relational expression. Analysis of seismic response data confirms that the proposed method can estimate the 1st, 2nd, and 3rd horizontal mode responses from the vertical vibration.

Study on vibration characteristics of elevator ropes by elemental test

Elevators are essential for means of a vertical transportation. Recently, high-rise buildings are increasing. Those elevator ropes become longer. As a result, the natural period of the elevator rope becomes closer to the natural period of the high-rise building. The risk of resonance increases. When the high-rise buildings receive an external force such as the strong wind and the earthquake, the elevator rope may sway intensely. The rope may be hooked to the equipment in the hoistway. The accurate analysis of a rope is important to grasp the actual rope behavior during an earthquake. In this study, the free vibration test on elevator ropes is carried out with an element testing equipment. Furthermore the vibration characteristic of elevator ropes is investigated. In this paper, the free vibration test was carried out with the 5 mm-diameter elevator rope, further the vibration characteristic was investigated. As a result, it was confirmed that the damping ratio of the elevator rope depends on the displacement of the horizontal direction.

Rope tension analysis based on single spring model against elevator rope

Elevators run vertically by suspension ropes, therefore each rope has to be adjusted correctly to fulfill each tension balance. That contributes to establish a long life against elevator ropes. If a groove wear of the traction sheave causes difference against other grooves, the difference induces rope tension fluctuation while changing the car position. Conventional elevator models to evaluate the rope tension have not considered the detailed winding behavior of the rope on the sheave. As the winding amount of the rope contains the rope deformation, the deformation should be considered to evaluate the rope length and the rope tension in an elevator tension model. This paper shows a simple elevator model with a single spring model against the rope. The derived model can not only calculate the appropriate winding amount against the rope spring model, but also get a faster solution even though the elevator system has a complicated roping configuration. The proposed simulation model is validated by experiments.

Rope tension analysis based on single spring model against elevator rope

Rope tension analysis based on single spring model against elevator rope

Damping force of air acting on vibrating elevator rope

Damping force of air acting on vibrating elevator rope

Vibration analysis of elevator rope

When an elevator rope for a high-rise building is forcibly excited by long-period ground motion, rope displacement becomes large even if the ground acceleration and the buildings acceleration is small. Therefore, in order to prevent damage to the elevator, an accurate estimation of rope behavior is required. This paper introduces the following topics;(1) relation between damping factor and magnification factor/response curve of rope (string model), (2) vibration characteristics of rope (string model) with vibration suppressors, (3) estimation method of 3 parameters (equivalent flexural rigidity, viscous damping ratio, structural damping ratio) of rope (beam model).

Application of Absolute Nodal Coordinate Formulation in Calculation of Space Elevator System

The space elevator system is a space tether system used to solve low-cost space transportation. Its high efficiency, large load, reusability and other characteristics have broad application prospects in the aerospace field. Most of the existing mechanical models are based on “chain-bar” and a lumped mass tether model, which cannot effectively reflect the flexible behaviour of the rope of space elevator system. To establish an accurate mechanical model, the gradient deficient beam elements of the absolute nodal coordinate formulation (ANCF) are used to build the mechanical model of the space elevator system. The universal gravitation and centrifugal force in the model are derived. The calculation results of the ANCF model are compared with the results of the finite element method (FEM) and lumped mass (LM) models. The results show that the calculation results of the ANCF method are not very different from the results of the FEM and LM models in the case of axial loading. In the case of lateral loading, the calculation results of the ANCF method are basically the same as the results of the FEM and LM models, but can better reflect the local flexible deformation of the space elevator rope, and have a better calculation stability than FEM. Under the same calculation accuracy, the ANCF method can use fewer elements, and the speed of convergence is faster than the FEM and LM models.

Study on improving the reproducibility of analysis considering the damping characteristics of rope vibration obtained from the free vibration test of elevator rope

Study on improving the reproducibility of analysis considering the damping characteristics of rope vibration obtained from the free vibration test of elevator rope

Vibration Analysis of Elevator Rope with Vibration Suppressors

Vibration Analysis of Elevator Rope with Vibration Suppressors

Simple Analysis of Elevator Rope Sway with Varying Length

Simple Analysis of Elevator Rope Sway with Varying Length

The Effect of Flexural Rigidity and Damping on Vibration Characteristics of Elevator Rope with Vibration Suppressor

The Effect of Flexural Rigidity and Damping on Vibration Characteristics of Elevator Rope with Vibration Suppressor

Vibration analysis of elevator rope with vibration suppressors (Identification of flexural rigidity, viscous damping and structural damping)

Vibration analysis of elevator rope with vibration suppressors (Identification of flexural rigidity, viscous damping and structural damping)

Consideration of some non-linear phenomena of elevator rope

Consideration of some non-linear phenomena of elevator rope

Laboratory Device for Checking the Functionality of the Elevator Rope Sensors

Abstract The paper describes the structural design of a laboratory device that allows for presenting operation, simulating work procedures and checking functionality of the elevator “rope sensors” when equalizing different tensile forces in partial ropes of a rope system of traction elevators. The laboratory device is modified for checking operations of commonly used rope sensors. In an overwhelming number of cases, elevator technicians use them for setting up the unequally distributed tensile forces in elevator ropes. The device is equipped with three, mutually attached pulleys, over which the rope is installed. The unknown tensile force in the rope is determined by an “indirect method”, i.e. from the resultant of the forces of the rope bent over the pulleys, which have an effect on the force sensor. The tensile force along the rope axis can be determined numerically, but also experimentally, from the inclination angle of the rope installed on the pulleys, diameter of the pulleys, diameter of the rope and the force detected by the force sensor of the stretched rope. The paper presents experimentally obtained tensile force values at the rope sensor, deduced from stretching the rope. The paper also describes the procedure for determining the measured load in the rope by rope sensors of the SWR, SWK and RMT-1 types based on the variable axial force in the rope.

A Study on the Development of an Elevator Rope Tension Automatic Equalizer

A Study on the Development of an Elevator Rope Tension Automatic Equalizer

Coupled Vibration Mechanism between Vertical and Horizontal Direction against Elevator Rope

Coupled Vibration Mechanism between Vertical and Horizontal Direction against Elevator Rope

Avoiding Resonance between Building Sway and Elevator Rope Based on Negative Stiffness

Avoiding Resonance between Building Sway and Elevator Rope Based on Negative Stiffness

Study on Prediction Method of Maximum Amplitude of Elevator Rope Forced by Earthquake

Study on Prediction Method of Maximum Amplitude of Elevator Rope Forced by Earthquake

Numerical Calculation Method of Elevator Rope Sway and Investigation of Displacement Magnitude under Resonance Condition

Numerical Calculation Method of Elevator Rope Sway and Investigation of Displacement Magnitude under Resonance Condition