DYNAMIC MESH ADAPTIVE COMPUTATION FOR ANCF-BASED FLEXIBLE CABLES VIA CURVATURE CONTINUITY

As a typical large-deformation flexible structure, flexible cables are widely used in aerospace, marine engineering and other fields. The accuracy and efficiency of their dynamic simulation are highly dependent on mesh generation strategies. Traditional fixed mesh methods often suffer from a trade-off between accuracy and efficiency due to insufficient discretization in large-deformation regions and excessive discretization in small-deformation regions, which makes it difficult to meet engineering requirements. To address this challenge, this study establishes a flexible cable element model based on the Absolute Nodal Coordinate Formulation (ANCF). From the equilibrium equation of the flexible cable, the element residual expression is derived. Through theoretical and numerical verification, the intrinsic correlation between the nodal curvature jump value and the residual is revealed. Based on this finding, this study overcomes the limitations of traditional methods and innovatively proposes curvature continuity as the core discriminant index for adaptive mesh generation. This approach effectively avoids the drawbacks of cumbersome equilibrium equation construction and large additional computational cost of mainstream residual estimation methods in adaptive finite elements for complex systems. Furthermore, an adaptive mesh update strategy that realizes element splitting and merging through dynamic node addition and deletion is constructed to achieve precise allocation of mesh resources. Simulation results show that the proposed method can accurately capture the configuration changes of flexible cables while ensuring energy continuity: elements in large-deformation regions are automatically refined to guarantee accuracy, whereas elements in small-deformation regions are simplified to improve efficiency. By adjusting adaptive threshold parameters, the accuracy and efficiency can be flexibly regulated to achieve their optimal balance. This study provides a computation scheme with both accuracy and efficiency for the dynamic analysis of large-deformation flexible structures, which can be extended to complex multibody systems. It also offers theoretical support for the design optimization and engineering application of cables in aerospace, marine engineering, and rope-driven mechanisms of manipulators.