Laboratory Device for Checking the Functionality of the Elevator Rope Sensors

AbstractThe 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.

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Testing Device for Hydraulic Rope System Tensile Force Equalizing Unit

Mechanics and Mechanical Engineering ◽

10.2478/mme-2021-0004 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Leopold Hrabovský ◽

Karel Frydrýšek

Keyword(s):

Tensile Force ◽

Small Diameter ◽

Bearing Steel ◽

Point Of View ◽

Correct Operation ◽

Load Bearing ◽

Actual Weight ◽

Tensile Forces ◽

The Given ◽

Rope System

Abstract Rope elevators, also referred to as traction elevators, have a cabin suspended from a system of ropes. The system of ropes consists of at least two load-bearing steel ropes with six strands or, from the point of view of easier bending, and currently more widespread, ropes with eight strands. Lifting or lowering of the car, run between the guides, is ensured by the frictional force of the steel ropes in the grooves of the traction disk of the elevator machinery. As the load-bearing capacity of the elevator increases, the required number of load-bearing ropes also increases, especially in the case where small diameter ropes are used in traction elevators. The actual weight of the car and the weight of the load must be evenly distributed among all supporting ropes that are used in the given layout of the elevator. Currently, several principles are known by which it is possible to detect and also change the values of the instantaneous magnitudes of the tensile forces acting in a system of ropes. The paper describes the principle of operation of hydraulic balancing of tensile forces in the system of supporting ropes, which uses the laws of hydromechanics and knowledge of pressure transfer to any place in the fluid, known as Pascal's law. Balancing of differently set values of tensile forces in three supporting ropes, to values of the same size, can be simulated on a test device. This presents the correct operation of the hydraulic system and the possibility of balancing tensile forces in the system of supporting ropes described by the principle of hydraulic device.

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Cable Tensile Forces Associated to Winch Design in Tethered Harvesting Operations: A Case Study from the Pacific North West

Forests ◽

10.3390/f12070827 ◽

2021 ◽

Vol 12 (7) ◽

pp. 827

Author(s):

Omar Mologni ◽

Eric D. T. Nance ◽

C. Kevin Lyons ◽

Luca Marchi ◽

Stefano Grigolato ◽

...

Keyword(s):

Endurance Limit ◽

Tensile Force ◽

Force Analysis ◽

North West ◽

The Pacific ◽

Work Tasks ◽

Tensile Forces ◽

System Activation ◽

The Impact

Cable tensile forces in winch-assist harvesting have been investigated in order to assess the safety concerns of the technology. However, the literature is lacking, particularly in regards to the impact of winch design. In this study, a Summit Winch Assist tethering a feller-director on ground slopes up to 77% was monitored for four days. The cable tensile forces were simultaneously recorded at the harvesting and anchor machine at a frequency of 100 Hz. Cameras and GNSS devices enabled a time study of the operations and the recording of machine positions. Winch functionality and design were disclosed by the manufacturer and used for the interpretation of the results. The cable tensile forces reached 296 kN at the harvesting machine and 260 kN at the anchor machine. The slow negotiation of obstacles while moving downhill recorded the highest peaks, mainly due to threshold settings of the winch in the brake system activation. Lower but significant peaks were also recorded during stationary work tasks. The peaks, however, were limited to a few events and never exceeded the endurance limit of the cable. Overall, the study confirmed recent findings in cable tensile force analysis of active winch-assist operations and provided evidence of the underlaying mechanisms that contribute to cable tensile forces.

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Experimental Evaluation of Tensile Forces in Short Steel Rods

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.732.333 ◽

2015 ◽

Vol 732 ◽

pp. 333-336 ◽

Cited By ~ 2

Author(s):

Michal Polak ◽

Tomáš Plachy

Keyword(s):

Tensile Force ◽

String Model ◽

Beam Model ◽

Building Structures ◽

Structural Elements ◽

Frequency Method ◽

Natural Modes ◽

Tensile Forces ◽

Torsion Springs ◽

Fixed Beam

There are a lot of structures in building and civil engineering where the significant structural elements are loaded by large tensile forces (e.g. tension bars of building structures). In many practical cases it is important to know the actual value of tensile forces in tensile structural elements for assessment of their reliability. The four experimental techniques are used for determination of tensile forces in practice most often. The vibration frequency method, which is one of them, is very suitable for experiments done only one time or sometimes, especially in cases when the examined structural elements are already activated and the application of an experimental method is necessary in this situation. The experiment described in this paper was focused on the tensile force determination in steel rods, which were very short and relatively stiff. The evaluated tensile forces of the investigated short steel rods were affected by a significant error when only the simplest models (the string model, the simply supported beam and the fixed beam) and measured natural frequencies were applied. In order to precise the determined tensile forces, the theoretical beam model supported by simple supports with torsion springs (“the elastically fixed beam”) and the measured natural modes of the rods had to be necessarily taken into account.

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Hydrostatic Force Sensor for Robotic Applications

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.2801201 ◽

1997 ◽

Vol 119 (1) ◽

pp. 115-119 ◽

Cited By ~ 2

Author(s):

H. Kazerooni ◽

Mark S. Evans ◽

J. Jones

Keyword(s):

Experimental Investigation ◽

Strain Gage ◽

Failure Modes ◽

Force Sensor ◽

Pressure Change ◽

Theoretical Derivation ◽

Mathematical Expressions ◽

Hydrostatic Force ◽

Tensile Forces ◽

Robotic Applications

This article presents a theoretical and experimental investigation of a new kind of force sensor which detects forces by measuring an induced pressure change in a material of large Poisson’s ratio. In this investigation, we develop mathematical expressions for the sensor’s sensitivity and bandwidth, and show that its sensitivity can be much larger and its bandwidth is usually smaller than those of existing strain-gage-type sensors. This force sensor is well-suited for measuring large but slowly varying forces. It can be installed in a space smaller than that required for existing sensors. This paper also discusses the effects of various parameters on the sensor’s performance and on failure modes. To verify the theoretical derivation, a prototype force sensor was designed and built. This prototype hydrostatic force sensor can measure the compressive forces up to 7200 lbf and tensile forces up to 3500 lbf.

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Experimental Study on Tensile Properties of Sugarcane Leaves

Applied Engineering in Agriculture ◽

10.13031/aea.14170 ◽

2021 ◽

Vol 37 (4) ◽

pp. 615-621

Author(s):

Jing Bai ◽

Shaochun Ma ◽

Jiwei Hu ◽

Yi Wei ◽

Fenglei Wang ◽

...

Keyword(s):

Moisture Content ◽

Tensile Properties ◽

Tensile Force ◽

Testing Machine ◽

Longitudinal Direction ◽

Leaf Sheath ◽

List Type ◽

Factors Affecting ◽

Strong Linear Correlation ◽

Tensile Forces

Highlights This article focuses on the tensile properties of sugarcane leaves. The moisture content and sheath diameter were selected as test factors, and the test index was the stalk-leaf connecting force. The load-displacement curves of stalks and leaves were plotted. Two-way ANOVA was also discussed. Abstract . The tensile properties of sugarcane leaves are critical factors affecting the harvesting quality of sugarcane harvesters. Thus, it is important to investigate the tensile properties of sugarcane stalks and leaves. The selected test factors were leaf moisture content and sheath diameter, and the stalk-leaf connecting force was selected as test index. The tests were conducted with two moisture content levels of 15% and 20%, and three sheath diameters of 22, 26, and 30 mm. The stress-strain curves of stalks and leaves were plotted to show how the tensile force varied during the tensile test. The results showed that there was a strong linear correlation between the stalk-leaf connecting force and diameter of leaf sheath, and the connecting force also increased with the increasing moisture content. In addition, leaf tensile forces in longitudinal direction were much larger than in transverse direction. Two-way ANOVA revealed that both of the moisture contents (A) and sheath diameters (B) had significant effects on the stalk-leaf connecting force (p < 0.01), however, the interaction between A and B was not significant (p > 0.1). This study provides a theoretical reference for the design and improvement of crop dividers of sugarcane harvester. Keywords: Moisture content, Sheath diameter, Stalk-leaf connecting force, Sugarcane leaves, Universal testing machine, Tensile properties.

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Development of a Novel Micro-Gripper Integrating Tri-Axial Force Sensor

First International Conference on Integration and Commercialization of Micro and Nanosystems, Parts A and B ◽

10.1115/mnc2007-21035 ◽

2007 ◽

Author(s):

Jiachou Wang ◽

Weibin Rong ◽

Lining Sun ◽

Hui Xie ◽

Wei Chen

Keyword(s):

Axial Force ◽

Crystalline Silicon ◽

Force Sensor ◽

Calibration Method ◽

Deep Reactive Ion Etching ◽

Micro Gripper ◽

The Cross ◽

Silicon Frame ◽

High Level ◽

Cross Structure

A novel micro gripper integrating tri-axial force sensor and two grades displacement amplifier is presented in this paper, which bases on the technology of Piezoresistive detection and use PZT as its micro driving component. The micro tri-axial force sensor is fabricated on a single-crystalline-silicon by the technology of MEMS and consists of a flexible cross-structure realized by deep reactive ion etching (DRIE). The arms of the cross-structure are connected to a silicon frame and to the central part of the cross-structure. After modeling the amplifier structure of micro gripper and the sensor, finite element method (FEM) is used to analyze the displacement of the micro gripper and the deformation of the cross-structure elastic cantilever. A calibration method of tri-axial sensor based on the technology of microscopic vision and the principle of bending deflection cantilever is proposed. The experimental verified that the sensor are high level of intrinsic decoupling of the signals from strain gauge, high resolutions in all three axes, high linearity and repeatability and simple produce of calculation. And also show the micro gripper is reasonable and practical. The sensor is capable of resolving forces up to 10mN with resolution of 2.4μN in x axis and y axis and up to 10mN with resolution of 4.2μN in z axis; the gripping displacement of the micro gripper is from 20μm to 300μm.

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A new method for calculating the combined anchor-concrete support of underground structures

MATEC Web of Conferences ◽

10.1051/matecconf/201817003023 ◽

2018 ◽

Vol 170 ◽

pp. 03023 ◽

Cited By ~ 9

Author(s):

Mikhail Pleshko ◽

Besarion Meskhi ◽

Marianna Pleshko

Keyword(s):

Negative Impact ◽

Tensile Force ◽

Underground Structure ◽

Soil Mass ◽

Regulatory Elements ◽

New Method ◽

Underground Structures ◽

Emergency Situations ◽

Tensile Forces ◽

Surrounding Soil

The problematic aspect of the underground structures construction in the urban area is the negative impact of construction on neighboring buildings and structures. To exclude emergency situations, it is required to control the interaction of the support of the underground structure and the surrounding soil mass by including additional regulatory elements, such as anchors, in the system. The article presents a new method for calculating the anchor-concrete support of underground structures and the results of monitoring of tensile forces in the bolting. It has been established that the tensile force has the highest constant value at the well mouth - jointing of the anchor rod, and then decrease exponentially.

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Analysis of Coupled Bending-Axial Vibration of a Rotor

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.662.608 ◽

2013 ◽

Vol 662 ◽

pp. 608-611 ◽

Cited By ~ 1

Author(s):

Jian Feng Ye ◽

Chun Long Zheng ◽

Xue Shi Yao

Keyword(s):

Axial Force ◽

Vibration Frequency ◽

Torsional Vibration ◽

Stiffness Matrix ◽

Tensile Force ◽

Vibration Frequencies ◽

Axial Vibration ◽

Bending Vibration ◽

Centrifugal Load ◽

Rotor Model

Aiming at a rotor model, the coupled bending-axial vibration is being analyzed.Calculation results show that the prestress relative to rotational centrifugal load may influence bending vibration frequencies of a rotor.The bending vibration frequencies will increase when the prestress increases.The axial vibration frequency has not an influence because the direction of the spinning prestress is perpendicular to axis.When a rotor is applies axial force, a compressional force will tend to increase the axial vibration frequencies while a tensile force will decrease the axial vibration frequencies.The effects of the prestress(centrifugal load )of the spinning rotor and the axial prestress can be accounted by an adjustment of the stiffness matrix for analysis.By use of the stiffness matrix,the changed axial and bending vibration frequencies can be explained.The coupled bending-axial vibration may take place when the bending vibration frequencies have increased in the state of the changed prestress.In the end, the coupled bending-axial vibration frequency can be calculated.On the basis of prestress, the coupled lateral-torsional vibration and the coupled torsional-axial vibration frequency can be analysed,similarly.

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