Changes in wire curvature as a wire rope is bent over a sheave

1995 ◽  
Vol 30 (4) ◽  
pp. 271-281 ◽  
Author(s):  
R E Hobbs ◽  
S Nabijou
Keyword(s):  
Outer Layer ◽  
First Principles ◽  
Wire Rope ◽  
Wire Ropes ◽  
Double Helices ◽  
Circular Arcs ◽  
Innermost Layer ◽  
Free Bending

The changes in curvature in single and double helices as they are bent into circular arcs are derived from first principles. This analysis is applied to wire ropes to examine the bending strains in the wires of a frictionless rope as it is bent over a sheave. It is shown that the free bending strains in the wires in the innermost layer of a strand in a rope taken as an example are higher than those in the outer layer wires, while the second wire layer has the lowest bending strains.

Contact Problems in Wire Ropes

1979 ◽  
Vol 101 (4) ◽  
pp. 702-710 ◽  
Author(s):  
S. D. S. R. Karamchetty ◽  
W. Y. Yuen
Keyword(s):  
Contact Point ◽  
Contact Problems ◽  
Wire Rope ◽  
Computer Method ◽  
Wire Ropes ◽  
Basic Model ◽  
Contact Points ◽  
Double Helices

Forces are transmitted across the contact points in a wire rope. Wires tend to bend in between the contact points and they tend to nick and cut at the contact points. A computer method is discussed to determine the contact points in a wire rope. In a geometrically perfect wire rope with the wires laid as double-helices no contact point occurs. But in an actual rope, the geometry changes while laying and due to loading, thus permitting contacts at a number of points. The paper discusses such contact points. Some refinements of the basic model were considered and results presented.

Arrangement Characteristics and Wear Distribution of Wire Rope in Parallel Grooved Multi-Layer Winding

2013 ◽  
Vol 423-426 ◽  
pp. 842-845 ◽  
Author(s):  
Zhi Hui Hu ◽  
Yong Hu ◽  
Ji Quan Hu
Keyword(s):  
Experimental Study ◽  
Wire Rope ◽  
Wire Ropes ◽  
The Wire ◽  
Wear Damage

Based on the analysis of multi-layer winding arrangement characteristic of the wire rope in Lebus drum, the experimental study is carried on wear distribution of the wire rope in parallel grooved multi-layer winding. The result shows that, the wire rope is arranged regularly in each drum area in parallel grooved multi-layer winding; the wear of wire ropes in crossover zone is more serious than that of the parallel zone; in the same-layer wire rope winding in crossover zone, the wear damage during the wire rope winding in crossover zone at the end of each-layer drum is the most serious.

Co-Simulation Procedure for Multibody Reeving Systems

2018 ◽  
Author(s):  
Grzegorz Orzechowski ◽  
Aki M. Mikkola ◽  
José L. Escalona
Keyword(s):  
Multibody System ◽  
Wire Rope ◽  
Rigid Bodies ◽  
Arbitrary Lagrangian Eulerian ◽  
Transverse Deformation ◽  
Absolute Position ◽  
Eulerian Approach ◽  
Wire Ropes ◽  
Simulation Procedure ◽  
Flexible Wire

In this paper, co-simulation procedure for a multibody system that includes reeving mechanism will be introduced. The multibody system under investigation is assumed to have a set of rigid bodies connected by flexible wire ropes using a set of sheaves and reels. In the co-simulation procedure, a wire rope is described using a combination of absolute position coordinates, relative transverse deformation coordinates and longitudinal material coordinates. Accordingly, each wire rope span is modeled using a single two-noded element by employing an Arbitrary Lagrangian-Eulerian approach.

Failure Analysis of a Redundant Reeving Hoist

1976 ◽  
Vol 98 (4) ◽  
pp. 1166-1169
Author(s):  
A. J. Edmondson
Keyword(s):  
Failure Analysis ◽  
Wire Rope ◽  
Single Component ◽  
Design Parameters ◽  
Component Failure ◽  
Wire Ropes ◽  
Lower Block ◽  
Critical Materials ◽  
Failure Conditions ◽  
Fail Safe

An analysis is presented of a reeving arrangement suitable for the hoisting of critical materials requiring fail-safe criteria. The system consists of two independent wire ropes symmetrically threaded through the crown and lower blocks and reeved by a single takeup drum. The analysis provides for the load in each line of the wire rope remaining after failure of one rope occurs. The motion of the lower block and load are also provided for the variety of failure conditions considered. The analysis is useful to predict the effect of various design parameters on the integrity of system in the event of a single component failure.

Cable and Wire Rope Barrier Design Considerations: Review

2003 ◽  
Vol 1851 (1) ◽  
pp. 95-104 ◽  
Author(s):  
Dean C. Alberson ◽  
Roger P. Bligh ◽  
C. E. Buth ◽  
D. Lance Bullard
Keyword(s):  
Cost Effective ◽  
Wire Rope ◽  
Crash Test ◽  
Test Results ◽  
Initial Tension ◽  
Wire Ropes ◽  
Serious Injuries ◽  
Horizontal Curvature ◽  
Crash Tests ◽  
Design Scenario

Cable or wire rope barrier was being used in the 1940s and maybe earlier for vehicle containment. Through the years the designs have changed, but engineers continue to see cable barrier as an inexpensive barrier for use in some roadside applications. Recently, cable or wire rope has gained popularity as a median barrier for the prevention of cross-median accidents. Cross-median accidents are typically violent collisions with a high probability of multiple serious injuries and deaths. Thus, the design trend is gravitating toward providing positive vehicle containment in wider medians for which barriers have not historically been warranted. Wire rope often provides a cost-effective solution for this design scenario. Field experience with cable or wire rope barriers has identified areas for design improvement. It is desirable that cables remain taut to improve interaction with the vehicle, reduce dynamic deflections, and minimize maintenance. Additionally, reduced design deflections result in more potential application sites. Recent research demonstrates that such improvements are practical and cost-effective. Besides the initial tension in the wire ropes, other factors that can have a significant influence on dynamic deflections include post spacing and horizontal curvature. Computer simulations with cable barriers with various post spacings and horizontal curvatures were used to develop guidelines for expected design deflections. Finally, full-scale crash tests were completed with a new, cost-effective cable terminal system, and a brief review of the design and crash test results is included.

The Fatigue and Degradation Mechanisms of Wire Ropes Bending-over-Sheaves

2011 ◽  
Vol 127 ◽  
pp. 344-349
Author(s):  
Zhi Hui Hu ◽  
Ji Quan Hu
Keyword(s):  
Failure Mechanism ◽  
Fatigue Failure ◽  
Mechanical Damage ◽  
Wire Rope ◽  
Stress Conditions ◽  
Degradation Mechanisms ◽  
Bending Fatigue ◽  
Wire Ropes ◽  
Combined Action

Fatigue failure behaviors caused by wire ropes bending-over-sheaves are discussed in the paper. Stress conditions of wire ropes bending-over-sheaves and the mechanism of damage to wire rope caused by fleet angel and angle of wrap is analyzed, the fatigue failure mechanism of wire ropes is investigated in the paper. The investigation indicates that the load and the mechanical damage of ropes bending-over-sheaves is very complex, and the fatigue failure of ropes bending-over-sheaves is the result of combined action of bending fatigue and various kinds of damage. The research will have implications to design and use of wire rope.

Large Wire Rope Mooring Winch Drum Analysis and Design Criteria

1980 ◽  
Vol 20 (02) ◽  
pp. 63-74
Author(s):  
K.K. Song ◽  
G.P. Rao ◽  
Mark A. Childers
Keyword(s):  
Modulus Of Elasticity ◽  
Lateral Pressure ◽  
Large Diameter ◽  
Wire Rope ◽  
Wire Ropes ◽  
Analysis And Design ◽  
Number Of Layers ◽  
Inadequate Knowledge ◽  
Wire Strand ◽  
Elasticity Number

Abstract Flange splitting (separation of the flange from the barrel) is the most common structural failure in large mooring winches. Conventionally designed winches have failed on a number of occasions when wire ropes 3 to 3.5 in (7.6 to 8.9 cm) in diameter and up to 10,000 ft (3048 m) long were employed for mooring large construction barges and semisubmersible offshore drilling units. It is believed that this is due to improper approximation of the field loading patterns on the winch, inadequate knowledge of patterns on the winch, inadequate knowledge of actual forces transmitted onto the flange and drum barrel of the winch, and/or defects in the structural joint between the flange and the drum barrel.The available design methods are often empirical, modified, or extrapolated from work done a decade ago using very small wire ropes and drums. The application of these techniques to a multilayered winch using large-diameter wire rope has proved to be unrealistic. A method is presented to calculate the flange thrust load and the barrel external pressure for winches using large-diameter mare ropes. Also, a general guide for design and analysis of such winches and the effect of the lateral modulus of elasticity of wire rope on the reduction in the layer tensions is presented. presented. Introduction Large wire rope winches increasingly are coming into use for offshore construction, pipe laying, and drilling vessels operating in deep water because of the advantages of mooring with wire or a combination of chain and wire as opposed to mooring with chain only. Winches using wire ropes 3 to 3.5 in. (7.6 to 8.9 cm) in diameter, up to 5,000 to 10,000 ft (1524 to 3048 m) long, and stacked up to 15 or more layers under high tensions have been in use. Even larger winches are being contemplated as the search for hydrocarbons and minerals expands into deeper water.An industry-wide survey revealed that several large winches used on lay barges and semisubmersible drilling units have failed in service, exposing the owners to millions of dollars in repair or replacement costs, plus the damaging downtime and delay to the programs on which these units were engaged. An programs on which these units were engaged. An indepth study into the probable causes of these failures revealed that the practical design of large winches remained empirical and that, in some instances, quality control in manufacture was not being taken seriously.Wire ropes, in general, are flattened when lateral pressure is applied. The amount of flattening or pressure is applied. The amount of flattening or compressibility varies according to lateral modulus of elasticity of wire rope, which is defined as the ratio of lateral pressure per unit length of rope to the decrease in rope diameter measured along the lines of pressure. When a wire rope is spooled on a drum, pressure. When a wire rope is spooled on a drum, due to compressibility, the applied line tensions at the middle layers tend to decrease significantly. Thus, the overall structural loading on the winch depends on the lateral modulus of elasticity, number of layers, number of wraps on each layer, and operational tension at each layer. The lateral modulus of elasticity is governed by the rope characteristics such as rope formation, method of weaving, type of core, wire strand and rope diameters, and material properties of core and wire strand. It is known that as the rope gets larger and stiffer, as the number of layers increase, and as the winding tension is maintained at a high level, the resulting forces on the barrel and the side flanges also increase. SPEJ P. 63

scholarly journals Quantitative Nondestructive Testing of Wire Ropes Based on Features Fusion of Magnetic Image and Infrared Image

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Shiliang Lu ◽  
Juwei Zhang
Keyword(s):  
Nondestructive Testing ◽  
Nearest Neighbor ◽  
Recognition Rate ◽  
Infrared Image ◽  
Wire Rope ◽  
Image Features ◽  
Magnetic Image ◽  
Wire Ropes ◽  
Processing Techniques ◽  
Modulus Maxima

Magnetic flux leakage (MFL) detection is one of the most widely used and best performing wire rope nondestructive testing (NDT) methods for more than a decade. However, the traditional MFL detection has the disadvantages of single source of information, low precision, easy to miss detection, and false detection. To solve these problems, we propose a method of fusion recognition of magnetic image features and infrared image features. A denoising algorithm based on Hilbert vibration decomposition (HVD) and wavelet transform is proposed to denoise the MFL signal, and the modulus maxima method is used to locate and segment the defect. An infrared image acquisition system was designed to collect the infrared image of the surface of the wire rope. Digital image processing techniques are used to segment infrared defect images. The features of the MFL image and the infrared image are extracted separately for fusion. The fusion feature is input into the nearest neighbor (NN) algorithm for quantitative identification, and the same data are input into the backpropagation (BP) neural network for comparison verification. The experimental results show that the fusion of MFL features and infrared features effectively improves the recognition rate of wire rope defects and reduces the recognition error.

Multi-loop magnetisation method for detecting coal mine wire rope defects

2020 ◽  
Vol 62 (9) ◽  
pp. 540-549
Author(s):  
Wang Hongyao ◽  
Tian Jie ◽  
Meng Guoying ◽  
Zhou Junying ◽  
Hua Gang
Keyword(s):  
Permanent Magnet ◽  
Coal Mine ◽  
Detection Method ◽  
Cost Effective ◽  
Wire Rope ◽  
Degree Of Saturation ◽  
Detection Accuracy ◽  
Test Model ◽  
Wire Ropes ◽  
Shape Structure

Existing methods for detecting magnetic leakage signals from damaged wire ropes require axial saturation magnetisation and the accuracy of the detection equipment depends on the degree of saturation of the magnetisation. Moreover, owing to the special characteristics of the structure, diameter and operating environment of the wire rope, it is difficult to achieve the expected magnetisation effect. Consequently, in addition to other issues, the detection accuracy and versatility of the equipment are low. This study proposes a method based on spatial multi-dimensional orthogonal array loop magnetisation to detect coal mine wire rope defects. First, a sensor excitation structure model is developed. Then, a method for detecting the radial magnetic flux using permanent magnet arrays is analysed and the influence of the number of permanent magnet radial magnetic blocks on the magnetisation effect is studied. In addition, a wire rope detection method based on the principle of clustering is investigated and used to discuss the influence of the shape, structure and size of the sensor on the magnetisation effect. Finally, through laboratory experiments, the applicability of the test model and the proposed method are verified. The results show that the magnetisation effect is better and more cost-effective when the number of permanent magnet radial magnetic blocks is eight and that the proposed detection method can effectively identify damaged wire rope joints. Furthermore, the proposed equipment achieves a signal-tonoise ratio of 28 dB, thereby improving the reliability of damage detection.

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