Deformation and crack prediction of CORC cable induced by Poisson effect: Theoretical modeling and experimental validation

The conductor on round core (CORC) cable exhibits superior mechanical properties compared with single superconducting tape due to its unique twisted cable structure, which allows for expansion through spiral winding. However, the deformation characteristics have not yet been effectively elucidated during the winding process. Especially, the shapes and distributions of internal damaged cracks are difficult to predict resulting from the multilayer structure of the superconducting tape. In this work, the theoretical model considering the spiral winding of CORC cables has been established and the deformation characteristics caused by the Poisson effect have been elaborated. Meanwhile, the theoretical model was confirmed by comparing finite element simulations, the accuracy and reliability were also verified by the stereo digital image correlation (stereo-DIC) experiments. It is shown that this model can predict the distribution characteristics of damaged cracks inside the superconducting tape multilayer structure during the winding process, which was further checked by magneto-optical imaging (MOI) experiments. Furthermore, the effects of twisted cable parameters on the deformation characteristics of the superconducting tape have been elucidated. These findings contribute to a deeper understanding of deformation in CORC cables during the winding process and offer guidance for their preparation and application.