The twisted, stacked-tape cabling method allows developments of high current REBCO cables for various high field applications, such as fusion magnets, magnetic resonance imaging (MRI) devices and accelerator magnets. The single tape performance under applied loads is crucial to understand cable limitations, and important for choosing an appropriate cable geometry. In this paper, we theoretically investigate the effect of twisting morphology on the mechanical properties of HTS tapes by using the Timoshenko beam model. Particular attention is paid to the transverse bending of a pre-twisted HTS tap. The analytical solution is first derived for the deflection of the HTS tap under a uniformly or periodically distributed transverse force. Then, the critical current of a twisted tape is calculated by the integration of the critical current densities corresponding to the strain distribution over the tape cross-section using axial strain data of the pre-twisted tape. The results show that the twisting morphology can significantly improve the resistance of HTS tap to transverse bending, thus reduce the superconducting performance degradation. This study helps understand the electro-mechanical properties of pre-twisted HTS taps and provides theoretical reference for the design of novel HTS cable structures.
Acknowledgments: The authors appreciate the financial supports from the National Natural Science Foundation of China (11572143 and 11421062).