Research On The Interaction Between Inclusion And Crack During Superconductor Magnetization

Bulk superconductors have great practical value because of its ability to capture high magnetic fields.Such as: medical equipment,transportation,electronic technology,high-energy physics and so on.However,it is inevitable that inclusions,cracks and other defects will occur in the production and preparation of high-temperature superconductors.When the superconductor is magnetized by the external magnetic field,the huge mechanical stress will be applied to the superconductor,and these stresses will often lead to the crack of tiny cracks,thus affecting the mechanical stability of superconductors.This will affect the practical application of superconductors and reduce the practical application value of superconductors.Therefore,the research on the mechanical properties of superconductors has always been the focus of scholars.In this paper,the interaction between inclusion and crack in a superconducting rectangular is discussed by considering the flux viscous flow during the magnetization of the superconductor,and the effect of flux viscous flow on the mechanical of superconducting thin film during magnetization.In chapter two,a model of a superconducting rectangular with inclusion and linear crack is established.By solving the Bean model and viscous flux flow equation at the same time,the influence of viscous flux flow on high-temperature superconductor with circular inclusion and linear crack is discussed,and the interaction between circular inclusion and linear crack in the superconducting rectangular is studied.Then,by using the method of plane strain and the finite element software ABAQUS for the simulation calculation.Discussed the decreasing of external magnetic during the zero field cooling process,the influence of the magnetic viscous flux flow rate,the radius of the inclusion,the length of the linear crack,the distance between the inclusion and the linear crack on the stress intensity factor at the crack tip.Then,a superconducting thin film analysis model is established to study the magnetization and magnetoelastic behavior of the superconducting thin film placed perpendicular to the external magnetic field during the rise of the external magnetic field.By considering the flux viscous flow factor,discuss the influence of viscous flux flow rate on current density distribution,flux distribution and normal stress distribution in superconducting films.The variation of the shielding region and the mechanical response with the viscous flux flow rate are analyzed.Based on the study and analysis of the mechanical response of the magnetization process of the superconducting rectangular plate and the superconducting thin film,this paper will provide some theoretical reference value for the mechanical properties and fracture properties of the superconductor magnetization process by considering the magnetic flux viscous flow factor.