Research On The Steel Wires’ Stress Distribution Law Of Cable And The Optimization Of Cable Clip Joint

Cable is the most important part in the tension structure system. Due to structure and processing technology of the cable, the mechanism of steel wires is quite complex. If it is assumed that the stress distribution of cable section is even, we will ignore negative extrusion effect between wires and uneven stress phenomenon, and underestimate the true stress in cable wires which may cause potential safety hazard. Therefore, it is important to undertand the stress distribution law for design staffs who will know how to arrange the cable and reduce material consumption. The purpose of this paper is to study the geometry and numerical modeling method of cable and cable clip joint, and discuss the stress distribution law of wires in the straight cable and cable clip joint of the hoop cable. It also discusses the cable clip joint optimization design methods and fatigue life of the cable. The main research contents include:1. Solid cable models of three wires, seven wires and nineteen wires are established accurately by using AutoCAD and ANSYS SCDM modeling software. Based on the finite element software Abaqus as the main platform and ANSYS Workbench as the auxiliary platform,"plane-to-plane" contact model is set up between wires, and the same stress condition and constraint condition are applied. Then the stress distribution and variation laws of cable wire section can be obtained by comparing the calculation results between two finite element softwares. The conclusion shows that:the results of two kinds of softwares are similar. The stress distributions of different layers’wires are not even, and the phenomen is more obvious for the inner layers’wires. The twist distance is longer as the wire’s location is outside. So when the cable diameter is large enough, the stress variation between layers tends to be gentle.2. The stress distribution law of the hoop cable in the cable clip joint is analysed by Abaqus, and a series of protective measures should be taken for the stress concentraton regions including optimization design of cable clip structure and adding the cushion, etc. The conclusion shows that:wires’ stress in the middle of the cable clip is even. The stress and initial tensile stress are basically the same. However, the wires in the both edges of the cable clip suffer extrusion by sharp corners so that the phenomenon of stress concentration is significant while the chamfers of cable clip improve the state obviously. Besides, on the basis of that, adding the cushion may ease the abrasion and extrusion to some extent between the cable and the cable clip, and relieve the collision energy. In addition, the protective performance of the rubber material is better than that of aluminum. The facts prove that the chamfers and adding the cushion are significant for different regions. Using both measures is suggested.3. Fatigue life of straight cable with3wires is analysed, and the approximate mathematical expression of the S-N curve of cable is estimated. The whole process of fatigue analysis is described. The fatigue dangerous area in the middle section of cable and the methods to improve the fatigue life are discussed.