Experimental Study and Fine-Tuned Simulation of Cable-Joint Pair Slipping in the Cable-Supported Structure

During the tensioning process of the cable-supported structure, the sliding friction between cable wires and joint will have a great influence on the mechanical properties of the structure. However, due to the complex structure of the cable and the combined action of bending deformation and large pre-tension at the cable-strut joint, it is difficult to accurately determine the coefficient of sliding friction (CSF) between cable wires and joint, and thus the overall mechanical properties of the structure cannot be accurately evaluated. Based on the twisting characteristics of the cable, this paper establishes a friction-slip test model and a refined numerical model to carry out detailed study of the mechanical behavior of contact between cable wires and joint during the tensioning process. Firstly, combined with the calculation results of contact mechanics, it is finds that the stress distribution at straight and curved sections of the cable are non-uniform along its axis and each cross section, and the non-uniformity coefficient of the internal force distribution of the cable is further quantified. At the same time, the local bending of the cable will intensify the uneven stress distribution in the circumferential direction of the cable. The non-uniformity of stress reveals the contact working mechanism of the cable-joint pair. Then, the change of the prestress loss between cable wires and joint with the tensioning process is analyzed, and the parametric analysis is conducted to reveal the effect of the cable included angle, tensile force, and lay length on the CSF. The results find that the prestress loss increases approximately linearly with the increase of tension force and decreases with the increase of the cable included angle, but the CSF is less affected by the lay length during the tensioning process. Finally, a method for valuing the CSF of the cable-supported structure is developed.