Bending behavior analysis of the Rutherford cable during the coil-end winding process

The High Luminosity upgrade of the LHC and the Hadron Future Collider study framework propose a new requirement of developing 16 T dipoles. Nb3Sn Rutherford cable is used to fabricate the superconducting magnets to achieve the goal. During the coil winding process, Rutherford cable's mechanical instabilities often occur at the coil ends, reducing the coil's performance and increasing the difficulty of the winding. In this study, a 1-axis bending model and a 2-axes bending model of the Rutherford cable are built and analyzed to better understand the mechanical behavior during the coil end winding process. The instabilities, such as opening, protrusion, and pop-out, are investigated. Several parameters' influence is considered in the analysis, such as the cable strands' twisting angle, the coil winding radius and orientation, and the friction.