Research on the Working Mechanism of Internal Steel Wires in a 1×19 Galfan-Coated Cable During Loading

In recent years， with the development of prestressed spatial structures， Galfan-coated steel cables have been widely used in engineering applications due to their excellent corrosion resistance and fire performance. To gain an in-depth understanding of the mechanical behavior of cables under complex loading conditions and the interaction mechanisms among internal steel wires， this study establishes a three-dimensional refined finite element model of a 1×19 Galfan-coated steel cable to simulate and analyze its mechanical response under axial tension and tension-bending coupling. The model defines the constitutive relation of the Galfan-coated steel wires， considers the contact between wires， utilizes rigid body coupling for boundary condition setting， and validates the accuracy of the finite element model by comparing it with experimental data. Analysis of the finite element simulation results reveals that： under axial tension， the influence of the friction coefficient on the contact pressure between wires varies with location； the Poisson effect and mutual misalignment between wires lead to a decrease in contact pressure， and the influence of the friction coefficient subsequently diminishes； the stress development in the wires is significantly affected by the lay angle， with the center wire （having no lay angle） exhibiting the fastest stress growth， while the outer layer wires grow slower due to the circumferential grip-wrapping effect； under tension-bending coupling， the variation trend of contact pressure is noticeably influenced by position， with the area below the center wire showing rapid growth due to greater tensile force， while the area above the center wire first decreases in contact pressure due to compression and then increases as the transverse load becomes dominant； furthermore， the stress distribution during cable bending exhibits significant inhomogeneity， with stress concentration areas being particularly prominent at the fixed ends and transverse load application regions， where alternating tension and compression is evident. The results indicate that the internal stress and contact pressure distribution of the cable under complex loading exhibit complex patterns； during tension， the wire lay angle plays a dominant role in stress development， while the bending effect significantly alters the distribution patterns of contact pressure and stress in the cable wires.