🤖 AI Summary
To address the low modeling accuracy and high computational cost associated with torsion–bending coupling in large-deformation simulations of highly flexible spatial beams, this paper proposes a novel three-dimensional Absolute Nodal Coordinate Formulation (ANCF) beam element based on the Bishop parallel frame. Unlike the conventional Serret–Frenet frame, the Bishop frame decouples curvature and torsion, avoids Euler-angle singularities, and enables geometrically exact, singularity-free torsion-deformable modeling. By integrating the Bishop frame into the ANCF framework for the first time—combined with continuum mechanics-based formulation and finite-element discretization—the proposed element achieves significantly improved simulation accuracy for problems involving strong spatial bending–torsion coupling and large torsional deformations, while reducing the number of degrees of freedom by over 30%. Dynamic response errors are reduced by an order of magnitude compared to conventional ANCF beam elements.