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.

The influence of rotation speed on the bending fatigue lifetime of steel wire ropes

2010 ◽  
Vol 225 (3) ◽  
pp. 520-525 ◽  
Author(s):  
Y A Onur ◽  
C E İmrak
Keyword(s):  
Rotation Speed ◽  
Steel Wire ◽  
Experimental Tests ◽  
Wire Rope ◽  
Experimental Investigations ◽  
Thermal Camera ◽  
Fatigue Lifetime ◽  
Bending Fatigue ◽  
Wire Ropes ◽  
Different Diameters

This article presents experimental investigations to determine the influence of rotation speed on the bending fatigue lifetime of rotation-resistant rope and non-rotation-resistant rope. Heat generated by the rotation speed on steel wire rope samples has been measured by a thermal camera. Two sheaves with different diameters have been used to obtain the effect of sheave diameters on the heat alterations and bending fatigue lifetime. Two experimental tests have been conducted to determine the effect of insufficient lubrication on the bending fatigue lifetime. The results indicate that rotation speed affects the steel wire rope lifetime subjected to bending fatigue.

Bending Fatigue Tests Using a Suitable NDT Method to Determine Lifetime of Large Diameter Wire Ropes for Offshore Lifting Applications

2008 ◽  
Author(s):  
Olav Vennemann ◽  
Rikard To¨rnqvist ◽  
Bjo¨rn Ernst ◽  
Sven Winter ◽  
Ian Frazer
Keyword(s):  
Fatigue Test ◽  
Large Diameter ◽  
Fatigue Tests ◽  
Wire Rope ◽  
Test Rig ◽  
Bending Fatigue ◽  
Wire Ropes ◽  
Bending Fatigue Test ◽  
Final Approach ◽  
Technical Effort

Wire rope for installations of subsea components offshore have been used for years in different configurations as single-fall or multi-fall. With greater water depths multi fall solutions become more challenging as even low torque ropes induce some torque and great technical effort has to be made to overcome this problem. An alternative solution is the use of a single-fall system employing a large diameter wire rope. Installations are often carried out with the aid of a heave compensation system to keep the load steady during final approach or to pass through resonance zones. As a result such a large diameter wire rope is subjected to frequent bending. It is well known that cyclic bending over sheave (CBoS) can significantly reduce the lifetime of ropes depending on rope utilisation factors and sheave diameters. While there is a lot of data available for smaller rope sizes, very limited data has been generated with large diameter ropes. It was therefore considered necessary to build a bending fatigue test rig and perform bending fatigue tests with the aim of reducing the uncertainty in the fatigue life of large diameter wire ropes. This paper presents the bending fatigue test rig capable of testing O̸109 mm wire rope to up to 330 t, describes the bending fatigue tests carried out and presents bending fatigue test results. Furthermore, results from non-destructive tests, which were frequently performed during the fatigue tests to obtain further information of rope deterioration over its lifetime, will be presented in this paper.

Fatigue Failure Mechanism of Steel Cords in Synchronous Belt

2003 ◽  
Author(s):  
Hideo Takahashi ◽  
Hiroshi Iizuka
Keyword(s):  
Finite Element ◽  
Failure Mechanism ◽  
Fatigue Failure ◽  
Outer Layer ◽  
Stress Component ◽  
Tooth Root ◽  
Element Analysis ◽  
Bending Fatigue ◽  
Steel Cords ◽  
Steel Cord

Synchronous belts are widely used as a power transmission element in many industrial equipments. The construction of the belts is a rubber and a helical cord as a tension member in the belts. The purpose of this study is to investigate the fatigue failure mechanism of the synchronous belts using steel cords. The steel cord focused here is 1*19 construction, that is made twisting nineteen steel wires. At first, the fatigue failure initiation site was found observing the failure morphology and measuring the belt deformation. Then, the fatigue failure mechanism was discussed with some fatigue tests of the steel cords and any mechanical and finite-element analysis. The belt failure was initiated near the tooth root, where the steel cords were fatigued. The belt curvature was measured by using the deformation of the marker lines that were put on the side surface of the belt. The belt was bent largely near the tooth root under high belt tension conditions. Namely, the belt was damaged by the bending fatigue near the tooth root. Then, the bending fatigue of the steel cord was tested and discussed the fatigue failure mechanism. The fatigue failure was firstly initiated in the outer layer wires. However, the bending stress was lower in the outer layer wires than in the core wire, according to a simple geometrical analysis. It is necessary to consider the initiation of another type of stresses based on the contact between the wires. Therefore, the finite-element was analyzed. We discussed the stress component that accelerated the fatigue failure in the outer layer wires. The friction force that was initiated between the wires well explained the acceleration of the fatigue failure in the outer layer wires.

Bending fatigue of single-wall and double-wall corrugated paperboards under sinusoidal and random loads

2021 ◽  
pp. 109963622110204
Author(s):  
Zhi-Wei Wang ◽  
Yang-Zhou Lai ◽  
Li-Jun Wang
Keyword(s):  
Energy Dissipation ◽  
Fatigue Failure ◽  
Fatigue Tests ◽  
Stiffness Degradation ◽  
Random Load ◽  
Bending Fatigue ◽  
Random Loads ◽  
Vibration Fatigue ◽  
Sinusoidal Load ◽  
Double Wall

The bending fatigue tests of single-wall and double-wall corrugated paperboards were conducted to obtain the εrms– N curves under sinusoidal and random loads in this paper. The εrms– N equation of corrugated paperboard can be described by modified Coffin–Manson model considering the effect of mean stress. Four independent fatigue parameters are obtained for single-wall and double-wall corrugated paperboards. The εrms– N curve under random load moves left and rotates clockwise compared with that under sinusoidal load. The fatigue life under random load is much less than that under sinusoidal load, and the fatigue design of corrugated box should be based on the fatigue result under random load. The stiffness degradation and energy dissipation of double-wall corrugated paperboard before approaching fatigue failure are very different from that of single-wall one. For double-wall corrugated paperboard, two turning points occur in the stiffness degradation, and fluctuation occurs in the energy dissipation. Different from metal materials, the bending fatigue failure of corrugated paperboard is a process of wrinkle forming, spreading, and folding. The results obtained have practical values for the design of vibration fatigue of corrugated box.

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.

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