Effect of Compaction Angle and Pre-Twist Pitch on Stress Distribution in Cable Core

To control the residual stress in stranded and compacted milliken conductors, this paper establishes a mechanical analysis model of the core that includes the entire pre-twisting and stranding processes. Using COMSOL software, the stress distribution in a five-segment 2500 mm² cable core is simulated, with a focus on investigating the influence of the compaction angle and pre-twist pitch on stress and deformation. The results show that the compaction angle affects stress by balancing axial tension and radial compression, while the pre-twist pitch regulates stress distribution through the competing mechanisms of geometric interference and bending deformation. When the pre-twist pitch is 1300 mm, a compaction angle of 70° minimizes the maximum displacement and maximum stress of the core to 0.0623 mm and 4.85×10⁷ N/m², respectively, representing reductions of 4.70% and 9.68% compared to those at 68°. When the compaction angle is 70°, the pre-twist pitch of 1300 mm yields the lowest maximum stress, which is 8.32% lower than that at 1200 mm. Under the combination of a 70° compaction angle and a 1300 mm pre-twist pitch, axial tension and radial compression reach an optimal balance, and geometric interference stress and bending deformation stress are well coordinated, leading to a significant reduction in residual stress. In this case, the compaction angle governs the forming mechanical path, while the pre-twist pitch optimizes the initial geometric shape; their synergistic interaction provides a theoretical basis and critical process window for the low-stress precision manufacturing of high-performance cable conductors.