The Influence Of Ferromagnetic Particles On The Magnetostriction And Effective Mechanical Properties Of Superconductor

Superconducting materials have many unique properties that ordinary materials do not possess,and have a wide range of applications.Ferromagnetic particle inclusions are very important functional materials composed of ferromagnetic particles and matrix elastic materials,both of which have been the focus of research in recent years.During the production and preparation of superconducting materials,various defects,including inclusions,may inevitably occur due to limitations in actual engineering conditions and processing environments.Previous studies on the inclusion problem in superconductors did not consider the case where the inclusion is ferromagnetic particles.This paper establishes a physical model of ferromagnetic particle inclusion superconducting matrix and studies the effective magnetostriction and other mechanical properties of composite materials under different conditions.Firstly,a simplified system of ferromagnetic particle inclusion superconductors was established based on the Bean model,and the relationship between the effective magnetostriction of bulk superconductors and elastic and magnetic parameters such as elastic modulus,volume fraction,and permeability was studied,taking into account the viscous flow of magnetic flux.Using the plane strain method for calculation,the distribution of displacement in superconductors is obtained based on stress,strain,and boundary conditions.Finally,the influence of ferromagnetic particles on the magnetostriction of bulk superconductors is discussed..Then a multi chain model of ferromagnetic particle inclusions in a superconducting substrate is established to investigate the effects of the distribution of ferromagnetic particle inclusions and elastic parameters on the effective magnetostriction of superconductors.Dimensionless parameters are introduced to describe the spatial distribution of ferromagnetic particles in the matrix,and the changes of effective magnetostriction with elastic parameters for three different distribution forms,namely,single chain,planar layered,and three-dimensional multi chain,are given.Based on the magnetic dipole theory and the Eshelby equivalent inclusion theory,the intrinsic strain is introduced and the uniform stress boundary condition is used to calculate the mechanical properties of the composite material.The effects of parameter changes such as the elastic modulus,volume fraction,and magnetic field of ferromagnetic particle inclusions on the effective mechanical properties of bulk superconductors,such as the effective elastic modulus,effective Poisson’s ratio,and effective magnetostriction,are compared in detail.Finally,in the fifth chapter of this paper,conclusions and prospects are given,providing a theoretical reference for the preparation of superconducting materials containing ferromagnetic particle inclusions.