Mechanical Stress in the Superconducting Film Under External Magnetic Field

In this paper, the mechanical response is studied for different superconducting films in magnetic field. When the superconductors are under the magnetic field, the electromagnetic body force will act on the sample. High mechanical stress can affect the mechanical and electromagnetic properties of the superconductors. Based on Maxwell's equations and the fast Fourier transform, the Lorentz force is obtained for the superconducting film during magnetization. We take into account the square and circular superconducting films with a finite-element method. In addition, the effects of notches and inclusion on the mechanical stress are presented. Numerical results indicate that square and circular films have similar stress distributions. In the same magnetic field, the stress along the axis is smaller in the superconducting film with notches or inclusion. Finally, the superconducting film with substrate is considered. Mechanical stability can be enhanced by the substrate.