The influence of magnetic field on the fracture toughness of soft ferromagnetic materials

This paper studies the effect of magnetic fields on the fracture toughness in nickel iron soft ferromagnetic materials. Tensile tests were conducted on single-edge cracked plate specimens in the bore of a superconducting magnet at room temperature, and the critical load was determined. The magnetoelastic analysis of a soft ferromagnetic strip with a single-edge crack was also performed, and the magnetic stress intensity factor was calculated. Based on the magnetic stress intensity factor, the fracture toughness was then obtained.