Mechanical behaviours of magnetoelastic interaction for superconducting helical magnets

After a theoretical model is proposed to characterize the magnetoelastic inter-action of superconducting magnets by means of the curved beam theory and the Biot-Savart law, a semi-analytical and semi-numerical method is employed to quantitatively analyze the magnetoelastic bending and stability of superconducting straight and torus helical coils in strong magnetic fields. In the proposed model, the effects of overall deformation modes, i.e. axial extension, torsion and bending, are considered. Having got the solution of magnetoelastic bending of a coil, the stability of the static equilibrium is claimed from the response of displacements of the structures in magnetoelastic bending with applied current by means of the Southwell plots. The results exhibit that the phenomenon of magnetoelastic instability is dependent on the parameters of geometry, especially on the ratio of pitch to (minor) radius.