Experimental Identification of the Overall Elastic Rigidities of Superconducting Windings

This study deals with an experimental methodology developed in order to identify the elastic properties of superconducting ring-shaped windings, constituents of the main coil winding of a magnetic resonance imaging magnet (MRI). Mechanical tensile tests were conducted on real scale specimens associated to an optical full-field displacement measurement technique (stereo image correlation). Strain fields were then obtained from the measured displacement fields by numerical differentiation. Finally, the four in-plane orthotropic stiffnesses of the windings were determined using the Virtual Fields Method (VFM). Experimental set-up also allows detecting a possible occurrence of a delamination thanks to in-plane displacement fields.