PSI - Issue 33

Anass Gouya et al. / Procedia Structural Integrity 33 (2021) 215–220 GOUYA Anass / Structural Integrity Procedia 00 (2019) 000–000

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1. Introduction Wire ropes are characterized by complex structures. they are usually obtained by assembling several strands helically and symmetrically wound, in one or more layers, around a straight central core (Jikal, Chaffoui, et El Ghorba 2019), [6]. They are mainly made of high carbon steel. Steel wires and usually textile elements are used to make up the ropes. Some ropes can be made entirely of metal. In most cases, they are made of a combination of steel wires and textile elements. The latter are used either as the core of the strands or as spacers between the metal strands (Zhang et al. 2019). Due to the difficulty and high cost of experimentation, numerical simulation methods are used in our work to study the mechanical behavior of strands with different configurations. In this work, numerical calculations are performed with Abaqus-CAE software by varying the diameters and pitches of wire ropes, for three different materials: aluminum, copper and steel. The objective is to optimize the best parameters for the mechanical properties, stress distribution, loading conditions at the interface between the steel wires and the failure process of the wire ropes under axial load, using the Taguchi’s method. A more powerful method called the Taguchi method, developed by Dr. Genichi Taguchi (Matejic et al. s. d.), a researcher at the Electronic Control Laboratory in Japan, in around the 1960s, was used to reinforce the conventional experimental methods (Asep, Ratna, et Ayu 2018). It should be noted that Taguchi exploited Ronald Fisher's experimental designs by improving them to make them more accessible to a wider public. The application of this method in electronics, automobiles and many other industries was a key factor in the rapid industrial growth (Jikal, Chaffoui, et El Ghorba 2019). G. Taguchi has been recognized in the field of quality for his contribution to the quality loss function, orthogonal tables, linear graphs and robustness, for illustration. Taguchi’s method is the evolution of force-strain and stress-strain at yield, the set of tests leading to specimen failure. Jikal et al. [1] presented a study on the effect of parameters on the elastic limit of central core strands of a wire rope based on the combination of the finite element method and the design of experiments by Yates’ method. A numerical study of spiral triangular strand and simple straight strand, taking into account the effect of the lay angle on the wire cross-section was established. The Finite element analyses indicated that non-linear global behaviors occur in both types of strands subjected to axial tensile and torsional loads, and showed that the discontinuous contact of the spiral triangular strand creates non uniform stress distribution [13effect]. This work aims to analyze and optimize the effects of manufacturing parameters of wire ropes on the failure stress behavior of central strands with different configurations. Furthermore, with the establishment of a Variance Analysis (ANOVA) using Taguchi method, the optimal parameters of these strands were determined. 2. Materials We have chosen a 19x7 wire rope with non-rotating structure (1x7 + 6x7 + 12x7) (the first number meaning the number of strands in the rope and the second number meaning the number of wires per strand), all the strands having the same length 200mm with different diameters (1.58mm-1.7mm-19mm) and different types of wire rope materials such as copper and aluminum and steel most usable in the field of mechanical engineering, and different pitch length (0°-114. 6-229.19°), in order to study the mechanical behavior of straight core strands extracted from this rope. The strands studied are composed of seven individual wires, a central wire and six peripheral wires arranged in a helix around the central wire (Jikal et al. 2019).

3. Results and discussions

3.1. Finite Element analysis of failure stresses The geometric model is imported into Abaqus/Explicit Finite Element software. The strand wires have the same material depending on the chosen material and a Poisson's ratio of =0.3. Each wire is assigned a solid section with a