Modeling the Effects of Biaxial Stress on Magnetic Properties of Steels with Application to Biaxial Stress Nde

Abstract This paper reviews recent work on the effect of biaxial stress on magnetic properties obtained from hysteresis loops. Both experimental and theoretical work are discussed. Biaxial stress measurements were performed on SAE-4130 and mild steel cruciform specimens. The theoretical model, applied to polycrystalline steels, reduces the problem to that of computing an effective stress and substituting that effective stress into the Schneider-Cannell-Watts model for uniaxial stress. The effective stress under biaxial stress is equal to plus or minus one of the deviatoric (i.e distortional) normal stress components. depending on whether tension or compression acts. and depending on which of the normal stress axes is parallel to the applied magnetic field. Computer results are compared to experimental results. Good qualitative agreement is found. An NDE procedure for determining the biaxial stress difference from magnetic properties is discussed.