Experimental determination of degradation influence on bending over sheave fatigue life of steel wire ropes (original) (raw)
Related papers
Effect of degradation and impaired quality on wire rope bending over sheave fatigue endurance
Engineering Failure Analysis, 2001
This paper reports the outcome of a series of tests undertaken on six strand and multi-strand ropes to investigate the eects of degradation and impaired quality on the rope's Bending-over-Sheave (BoS) fatigue endurance. The simulated degradation and quality impairment investigated were: wire breaks (internal and external); plastic wear, abrasive wear, corrosion, slack strands, slack wires and torsional imbalance. Theoretical predictions of rope fatigue endurance have been made to compare with the experimental values, using Feyrer's equation. The investigation indicates that the bending over sheave fatigue endurance of rope is little in¯uenced by degradation and impaired quality, which is primarily dependent on the rope construction and the diameter ratio of sheave to rope. The study establishes methodologies for assessment of the residual BoS fatigue endurance of degraded or impaired rope, which can inform the practical operation, inspection and discard of wire rope thereby enhancing safety.
2012
Steel wire ropes are used in elevators, cranes, mine hoistings, bridges, offshore and aerial ropeway systems. In this study, bending over sheave (BoS) fatigue lifetimes of 6 × 36 Warrington-Seale steel wire ropes have been determined theoretically and experimentally. Experimental findings have critical importance in identifying behavior of wire rope subjected to bending over sheave fatigue. Experimental studies have been performed to show effects of tensile load and sheave diameter parameters on BoS fatigue lifetimes of 6 × 36 Warrington-Seale steel wire ropes. Besides, a multiple linear regression model has been devised and novel theoretical BoS fatigue life prediction equation has been presented by using the least square method. The results indicate that there is a powerful correlation between the results obtained by theoretical model and experimental data. The BoS fatigue lifetime results can be used in the range of specific tensile loads investigated and diameter ratios used with acceptable error.
Experimental Techniques, 2017
Investigation on theoretical and experimental determination of bending over sheave fatigue lifetimes of rotation resistant steel wire ropes has been conducted. Effects of sheave size and tensile load on bending over sheave fatigue lifetimes of investigated rope have been presented. Bending over sheave fatigue life prediction according to effects of tensile load and sheave diameter has been presented by using artificial neural networks. The results point out that constructed ANN model estimations and experimental results have powerful correlation.
Discard fatigue life of stranded steel wire rope subjected to bending over sheave fatigue
Mechanics & Industry, 2017
In this study, discard lifetimes of 6 × 36 Warrington-Seale steel wire ropes subjected to bending over sheave (BoS) fatigue have been determined theoretically and experimentally. Multiple linear regression model has been devised and novel theoretical discard life prediction equation has been presented by using the least square method. The results indicate that there is a powerful correlation between the results obtained by theoretical model and experimental data. The theoretical discard life prediction equation results can be used in the range of specific tensile loads investigated and diameter ratios used with acceptable error when the values of coefficient of determination (r 2) and correlation coefficient (r) are considered.
Prediction of rope bending fatigue life based on wire breaking rate
FME Transactions, 2023
Steel wire ropes offer manufacturer-independent safety performance, while the durability performance can be different. To assess the damage status of a wire rope during its service, fail-safe methods are used, so it is necessary to know the progression of the damage to apply them. This paper proposes an analytical method for estimating the fatigue life of steel wire ropes. Using a dimensionless analysis, the characteristic damage curve of each rope category has been suggested, setting the basis of a predictive maintenance procedure extendable to all areas of rope application where bending fatigue is the first discard criterion for rope replacement. Rotary bending fatigue tests are performed on different rope construction specimens, and the evolution of broken wires is monitored. It has been demonstrated that the trend of breakage level is exponential with time, regardless of the type of rope and the stress level imposed.
Methodology for reliability assessment of steel wire ropes under fretting fatigue conditions
JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES, 2017
This paper describes a newly-developed damage-based fatigue life model for the longterm reliability assessment of drawn steel wires and wire ropes. The methodology is based on the computed local stress field in the critical trellis contact zone of a stranded wire rope by FE simulations and the estimated fretting damage of the drawn wire material. A case study using a single strand (1x7) steel wire rope with 5.43 mm-dia. drawn wires is employed to demonstrate the damage-based fatigue life prediction procedures. Under applied tensile loading with peak stress corresponding to 50%MBL (P = 145 kN, R = 0.1), the von Mises stress cycles in-phase and with an identical stress ratio to the applied axial load. The damage initiation life at the trellis contact along the core wire is No = 673 cycles with an additional 589 load cycles to reach the first separation of the material point. The threshold load cycle for the fretting fatigue damage is predicted to be 12.3%MBL. An improved data set of the damage model parameters of the drawn steel wires is indispensable in achieving an accurate and validated life prediction model.
Effects of different lay angles on characteristic fatigue responses of steel wire ropes
Nucleation and Atmospheric Aerosols, 2022
This paper establishes the effects of different lay angles of steel wire ropes on the resulting damage modes and fatigue fracture characteristics. For this purpose, seven-wire strand (1×7) wire ropes with left lay arrangement and lay angles, α of 11°, 18° and 24° were simulated using finite element (FE) method. Axial load cycles (Pmax = 0.144 minimum breaking load (MBL), R = 0.1) along with the Coulomb friction μ of 0.5 between the contacted drawn steel wires are assumed. Results showed that the peak contact pressure, corresponding to the maximum applied load, varies from 1936 to 327 MPa when the lay angle is changed from 11° to 24°. The peak of the localized pressure, at any applied load level, is also higher for a smaller lay angle. The wire rope with the lay angle of 24° experiences the smallest load-displacement hysteresis loop with the relative displacement range of 22 μm. On the other hand, the wire ropes with the lay angle of 11° and 18° develop larger hysteresis loops with the displacement range of 75 and 48 μm, respectively. The dissipated energy due to the frictional contact is 469 N.mm, 314 N.mm, and 132 N.mm for the lay angle of 11°,18°, and 24°, respectively. In addition, the axial stiffness of the wire ropes decreases with the increase of the lay angle. It is anticipated that the wire rope with the large lay angle of 24° would experience fretting fatigue failure associated with the partial slip, while those with smaller lay angles (α = 11°,18°) would fail by fretting wear mechanism under the gross slip condition.
Measurement, 2019
In this paper, theoretical and experimental studies are conducted to exhibit the discarding fatigue lifetime of a rotation resistant rope exposed to alternate bending over sheave (BoS) fatigue. Experimental studies are fulfilled to determine discarding lifetimes of a rotation resistant rope exposed to BoS fatigue. Multiple linear regression analysis is performed and novel theoretical discarding lifetime prediction formula is determined by using the least square method. Furthermore, discarding lifetimes of rotation resistant ropes exposed to BoS fatigue is predicted by using artificial neural network (ANN). There is a vigorous correlation among the results acquired by regression model, ANN and experimental data.
Fatigue Life Analysis of Wire Rope Strands with Finite Element Method
In this study, fatigue life of axial loaded wire rope strands are investigated in computer environment. For this purpose generated models about finite element analysis of wire ropes, conducted researches and fatigue condition of wire ropes are investigated. The condition required in order not to contact outer wires with each other is expressed with the purpose of modeling simple strand and the generated model is confirmed by using defined geometrical values. 3D solid model of 1+6 simple strand used in finite element analysis is generated in CAD software SolidWorks TM . Finite element analysis of simple strand is done by FEA software ANSYS TM . Fatigue analyses are done by ANSYS/Workbench for experimental groups generated by using 3 different parameters which are strand length, helix angle and force range. Graphics, which show fatigue life variance of axial loaded 1+6 simple strand, are created by obtaining fatigue life distribution according to Goodman approach.
Measurement of cyclic bending strains in steel wire rope
The Journal of Strain Analysis for Engineering Design, 2000
This paper reports strain gauge measurements of cyclic bending strain in the wires of a six-strand right-handed Lang's lay steel wire rope running on and off a pulley. The paper describes the measurement procedures and presents the results for the two tests conducted which had different gauge configurations along and around the sample. It was found that the strain waveforms observed had some similarities with those reported elsewhere and the magnitudes of strains matched theoretical predictions. However, in contrast with behaviour reported for fluctuating tension, the initial differences between and along wires rapidly attenuated. This observation helps to explain reported similarities in bending fatigue performance of ropes from different sources which contrasts with the very significant differences in characteristics found in tensile fatigue. The dependence of wire strain amplitude on rope bending deformation further contrasts with tensile fatigue in which wire strain range is...