Numerical Simulation of the Mechanical Properties of the $\hbox {Nb}_{3}\hbox {Sn}$ CICCs Under Transverse Cyclic Loads

Based on an improved discrete dynamical model, the mechanical properties of the cable in the Nb₃Sn CS1 conductor cross section under transverse cyclic mechanical loads are analyzed in this work. The first cyclic-load-displacement curve is numerically obtained and compared with existing measurements, and excellent agreement is achieved. It is obtained from further simulation results that the rearrangements of strands´ positions are very obvious, and the local void of petals significantly decreases after the first few cycles, which lead to the macroscopic plastic deformation of the cable. With the increase in load cycles, such plastic deformation may gradually tend to stability because of the enhancing constraints between strands under low local void fraction. Apparently, the microscopic rearrangement of strands is a critical factor in determining its macroscopic mechanical properties. Once such rearrangement of strands ends, the transverse stiffness and the mechanical loss also tend to be stable, and the cable in the CS1 conductor cross section is closer to elasticity.