Magnetoelasticity for large stresses

Recent interest in the theory and modeling of magnetoelastic processes has drawn upon the Preisach model of hysteresis' and the anhysteretic model'. We have extended our past work with the differential susceptibility model3 to stresses much larger than residual stress, reaching the local anhysteretic curve and the Villari reversal. Progress in this nonlinear differential magnetoelastic theory arises from the concept of local demagnetization. that is positive and negative stress-sensitive domain walls and stressinsensitive walls are attributed average local magnetization, U,. rather than global magnetization. an experimentally determined nonlinear demagnetization factor, Do, that replaces a function by Spano', and an improved approach to modeling hysteresis. Figure 1 shows good agreement between theory(so1id lines) and experiment' for HUT processes on our hollow cylindrical low carbon, Hi-Cr-hlo, high strength steel specimens Further studies. discussed in the full paper, confirm agreement between theory and experiment for u H , eTH and HRuB processes Here, e stands for the application of knsile or compressive strerr and s t r e s or field are applied or removed, starting from a demagnetized state. Magnetization changes are a sum over three domain wall types of an integral of the susceptibility over the local field for the removal of magnetic field, m established by Bozorth6. This model predicts the magnetization in the material