A parametric torsional model for nonlinear behavior of stranded cables: A finite element approach

• Indicated that stranded cables have different behaviour depending on the rotation direction. • Identified hysteresis loops in cyclic loading-unloading in the winding phase. • Obtained that the initial conditions have an effective role in the behaviour of stranded cables. • Achieved a torsional model of the specified structure for dynamic behaviour analysis. Stranded cable is a practical structure widely used in cranes, power transmissions, mining sectors, etc. The cable primarily comprises a core wire with helical wires whose geometric shape is a function of the intended usage. In this research, a torsional model based on the finite element method is presented with a beam element to investigate the cable’s performance within the elastic deformation region under coupled loads and various boundary conditions. After validation of the model with previous experimental and analytical results, a comprehensive investigation of the torsional behavior of a stranded cable under different conditions was carried out. The primary results reveal that the cables exhibit completely different responses in winding and unwinding of cables, and increasing loads in the axial direction amplify nonlinear torsional behavior owing to the mutual dependence on tensile and torsional forces. Due to the nonlinearity of the structure, the behavior of the cable is extremely sensitive to initial conditions, where slight variations in their magnitude have a significant impact on the mechanical response. The other notable observation is the presence of hysteresis in the winding of the structure under torsional loading and unloading. A parametric torsional model was also developed to examine the cable's dynamic performance through analytical and numerical simulations. This model is the first step towards dynamic modeling of stranded cables and their use to characterize cable behavior under combined loadings.