MICROMAGNETIC MODEL FOR THE INFLUENCE OF BIAXIAL STRESS ON HYSTERETICMAGNETIC-PROPERTIES

A micromagnetic formulation has been developed for modeling the effect of biaxial stress on magnetoelastic processes in polycrystalline stee ls. In particular, the formulation employs the Schneider-Cannell-Watts model and involves substitution of an effective stress equal to one o f the deviatoric (i.e., distortional) normal stress components, depend ing on whether the field is parallel to a tensile or compressive axis or to the third axis perpendicular to the plane of biaxial stress. Com puter results are compared to experimental results on the effects of b iaxial stress on magnetic properties in mild steel and in SAE-4130 ste el. Good qualitative agreement is found in almost all cases, in that i n going from one biaxial stress case to the next, the same kinds of ch anges are seen magnetically. It is also shown from the model and the d ata that a method can be formulated to nondestructively determine the difference in biaxial stresses.