Magnetostrictive behaviors of type-II superconducting cylinders and rings with finite thickness

Abstract

This paper presents an investigation of the magnetostrictive behaviors of type-II superconducting cylinders and rings with finite thickness in the presence of a uniform applied field directed along the axis by means of the minimization of magnetic energy and the finite element method. The dependence of the magnetostriction and mechanical response upon the geometry of the superconductors is systematically studied in terms of Bean's critical state model with consideration of the demagnetizing effects. The results show that the magnetostriction curves for different geometric shapes of cylinders and rings have different features. The magnetostriction curve has a larger vertical width for a finite cylinder with a smaller aspect ratio, however it shows reversal behaviour for a ring with specific shapes. Flux-pinning-induced displacement and stress distributions are also presented. Simultaneously, the spatial distributions of the radial, hoop and axial stress components in a whole superconductor are shown during field rise from the virgin state, and subsequent field descent. It seems that the mechanical response of a finite sample is similar to that of an infinitely long or a thin superconductor, but it also has a difference due to the boundary and demagnetization effects.

Simulation studies of mechanical stresses in REBaCuO superconducting ring bulks with infinite and finite height reinforced by metal ring during field-cooled magnetization

“…The compressive and tensile hoop stresses were, respectively, concentrated at the innermost peripheral edge of the infinite ring bulk during the ascending and descending stages of the PFM process, together with the compressive stress due to the thermal contraction by cooling. Huang et al investigated the magnetostriction of superconducting cylinders and rings with finite height by FEM [16], in which Bean's model and a uniform applied field using an infinite magnetizing solenoid coil were assumed. They concluded that the mechanical response of the finite height bulk is similar to that of an infinitely long bulk, but there is also a difference due to boundary and demagnetization effects.…”

Modeling and Parameter Sensitivity Improvement in ΔE-Effect Magnetic Sensor Based on Mode Localization Effect

“…The composite film’s material parameters and device geometry changes are meaningful and achievable based on currently available published works [ 56 , 62 , 63 , 64 ]. As shown in Figure 5 a, the relationship between the AR and magnetic field is calculated when the saturation magnetostriction changes from 50 ppm to 170 ppm.…”

“…The Material Properties of The WCR The magnetostrictive material is based on Fe-based soft ferromagnetic materials, and the parameters are reasonably selected based on the current works. The key material parameters used by the analytical model and FEM are given as follows [ 30 , 56 , 62 , 63 , 64 ]: The saturation magnetostriction ppm, the saturation magnetization , the effective magnetocrystalline anisotropy energy density KJ/m 3 , the in-plane easy-axis direction , the rotational deviation around the mean easy-axis angle , the energy density deviation around the mean easy-axis angle , and the static initial magnetic susceptibility . The AC voltage magnitude is V applied to the piezoelectric layer of R2, with the damping loss factor , Young’s modulus of the magnetostrictive layer GPa, Poisson’s ratio of the magnetostrictive layer , magnetostrictive material density kg/m 3 , the piezoelectric layer GPa, kg/m 3 , the substrate layer GPa, kg/m 3 .…”

“…The magnetostrictive material is based on Fe-based soft ferromagnetic materials, and the parameters are reasonably selected based on the current works. The key material parameters used by the analytical model and FEM are given as follows [ 30 , 56 , 62 , 63 , 64 ]:…”

Mechanical Stress in the Superconducting Film Under External Magnetic Field

“…In addition, The mechanical behaviors of thin superconducting disk with a concentric hole and rectangular superconducting slab with a central rectangular hole were studied [16,17]. Then, more complex structures or critical state model are considered to predict the mechanical deformation and stability [18][19][20]. The stress distribution of an infinite hollow superconducting cylinder was studied analytically [21].…”