Investigation on the Mechanical Behavior of the Prestressing Strand by the Finite Element Method

Wire ropes that have a wide range of applications endure loads, stresses, strains, and moments while carrying out the duty of carrying loads. Wire ropes and strands are frequently used as load carrying elements due to their flexible structure and being reliable products. A prestressing steel strand is a form of the pattern of 1x6 helical wires which supply extra stiffness. Contact conditions between adjacent wires, helical geometry of wires at outer layers make it difficult to find the mechanic response of wire ropes or strands under axial load. A good way to overcome this difficulty is to perform a computer-aided simulation with finite element method. In this study, a prestressing strand having 11.11 mm diameter is computer-aided modeled by using SolidWorks, and then ANSYS Workbench is used to determine the mechanical response of the investigated rope strand. The findings indicate that results remained in the elastic region in all finite element simulations until the strain value of 0.00728

Experimental and theoretical investigation of prestressing steel strand subjected to tensile load

In this study, the response of prestressing strands to axial tensile load is investigated theoretically and experimentally. Experimental data acquisitions of prestressing strand subjected to tensile load are performed by means of strain gages and linear variable differential transformer (LVDT). Feyrer's and Costello's theories are used for theoretical calculation of strain and stress values occurred on wires of prestressing strand. Linear regression model is devised to predict tensile load-strain and tensile stress-strain relations by using experimental results. Results indicate that there is a powerful correlation between results obtained by experimental data and linear regression model. © 2016 Elsevier LtdCouncil for Higher EducationThe author is immensely grateful to Prof. Michael G. Oliva who is faculty of University of Wisconsin-Madison for being advisor during postdoctoral study. Author was supported by Council of Higher Education for postdoctoral study

Theoretical investigation of rope strand subjected to axial tensile load

Wire ropes or rope strands are one of the most important load carrying components of transportation systems such as bridge, elevator, crane and mine hoisting. Wire ropes must have high tensile strength in order to carry high tensile load. Wire ropes are mainly subjected to axial tensile load in service. This axial tensile load is exerted upon wires of rope or strand. Due to this reason tensile load causes elongation, strain and stress on the center wire (core wire) and outer wires. In this study, theoretical calculations proposed by Feyrer are adopted in order to determine wire loads, stresses, elongations and strains for axially loaded rope strands. An illustrative example is given. © 2019 The Author(s

Investigation of the effect of the sling angle and size on the reliability of lifting hooks

The lifting hook is one of the vital components in material handling systems, since sudden accidents are unavoidable if the working reliability of the hook is poor. In this study, computer-aided single hook modeling is done in accordance with the DIN 15401 standard then extensive stress analyses at different sling sizes and angles and stress analyses when the hook is rigged by sling legs with unequal leg length and rigged by sling legs with unequal leg length and height have been conducted in order to reveal the effect of sling size and angle and different rigging manners on the safety factor of the lifting hook by using finite element simulation. Loads carried by each sling member are calculated and presented. Curved beam theory and simplified theory are employed to compare finite element simulation results. The critical sling angle at which the safety factor reduces evidently has been determined by altering the sling size and angle. The critical sling angle is found to be 51°, since reduction in the safety factor originates from a 51° sling angle. © The Author(s) 2017

Condition monitoring of Koepe winder ropes by electromagnetic non-destructive inspection

The objective of this study is to monitor four Koepe winder head ropes, which have six triangular-shaped strands and are 38 mm in diameter, by non-destructive inspection. The investigated ropes are frequently used in mining systems due to having a higher filler factor and resistance to abrasive wear, and the triangular shape contributes to a proper pressure distribution on the sheaves. In this study, three different non-destructive inspections have been performed on the investigated ropes and the results are presented. The non-destructive inspection results have been evaluated by considering international standards. The safety factors have been calculated and presented. Soaring wire break rates between the last two inspections and a maximum of 2.18% loss of metallic cross-sectional area in the fourth rope of the Koepe system have been observed. In addition, the maximum strength loss because of wire breaks in a 1 m length of four Koepe winder ropes has been found to be 9767 kg, and the safety factor reduction in personnel transportation and in material transportation have been found to be 2.37% and 2.36%, respectively

Discarding lifetime investigation of a rotation resistant rope subjected to bending over sheave fatigue

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. © 2019 Elsevier Ltd33137The authors acknowledge for permission performing our experiments in rope technology laboratory of University of Stuttgart This study was financially supported by Istanbul Technical University Scientific Research Fund (Project No. 33137 )

Investigation on Bending over Sheave Fatigue Life Determination of Rotation Resistant Steel Wire Rope

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. © 2017, The Society for Experimental Mechanics, Inc.33137Acknowledgement The authors acknowledge to directors of Institut für Fördertechnik und Logistik for our experimental work permission in their laboratory. This study is supported by Istanbul Technical University Scientific Research Fund (Project No. 33137)

Discard fatigue life of stranded steel wire rope subjected to bending over sheave fatigue

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 (r2) and correlation coefficient (r) are considered. © AFM, EDP Sciences 2017

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

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. © Authors 2010

Theoretical and experimental investigation of stress distribution in a crane hook

Crane hooks are frequently used in material handling systems for grasping loads to be lifted to keep them from dropping, thus preventing catastrophic accidents in such situations. In this study, the response of crane hooks to their payload is investigated theoretically and experimentally. The approximate calculation method and curved beam theory are used for a theoretical calculation of maximum and minimum normal stress values occurring on crane hook. In addition, a computer aided model of a crane hook, adhering to DIN 15401 is used, and a stress analysis is performed by means of finite element simulation. Experimental data acquisition regarding crane hooks and their payload are conducted by means of strain gage sensors. The theoretical method solutions and the experimental results are compared. The results obtained are in good harmony with the experimental measurements, curved beam theory and finite element analysis. © Carl Hanser Verlag GmbH & Co. KG.2017-77654622-02This study was supported by the Bulent Ecevit University Scientific Research Fund (Project No. 2017-77654622-02)