A Nonlinear Finite Element Analysis Method for Strand Structures Considering Tensile–Torsion–Bending Coupling Characteristics

The special configuration and elongated geometrical appearance of the helical strand give it properties of tensile–torsion–bending coupling as well as macroscopic geometrical nonlinearity. Simulating small-scale strands using solid elements in finite element software reproduces these properties but is time-consuming. Current methods of modeling large-scale strands using cable elements or beam elements can account for geometric nonlinearities, but often fail to adequately consider the tensile–torsion–bending coupling characteristics of the strand cross-section. This study presents a new finite element method for modeling strand structures. This analysis method adopts the rigid body rule to handle the geometric nonlinearity of strand structures, considering the tensile–torsion–bending coupling characteristics of the strand cross-section, while remaining acceptable in terms of analysis time. The analytical method can provide the strand structure’s displacement and the parameters of the tension–torsion–bending coupling characteristics of the strand element. The results obtained from the proposed analytical method were compared with those from numerical modeling and experimental testing, confirming the validity of the analytical method.