A THEORETICAL-MODEL OF MAGNETOELASTIC BUCKLING FOR SOFT FERROMAGNETICTHIN PLATES

As an essential model of magnetoelastic interaction between magnetic f ield and mechanical deformation, the study on magnetoelastic buckling phenomenon of soft ferromagnetic plates in a magnetic environment has been conducted. One of the key steps for the theoretical prediction of the critical magnetic field is how to formulate magnetic force exerte d on the magnetized medium. Till today, the theoretical predictions, f rom theoretical models in publications, of the magnetoelastic buckling of ferromagnetic cantilevered beam-plate in transverse magnetic field are all higher than their experimental data. Sometimes, the discrepan cy between them is as high as 100%. In this paper, the macroscope form ulation of the magnetic forces is strictly obtained from the microscop e Amperion current model. After that, a new theoretical model is estab lished to describe the magnetoelastic buckling phenomenon of ferromagn etic thin plates with geometrically nonlinear deformation in a nonunif orm transverse magnetic field. The numerical method for quantitative a nalysis is employed by combining the finite elemental method for magne tic fields and the finite difference method for deformation of plates. The numerical results obtained from this new theoretical model show t hat the theoretical predictions of critical values of the buckling mag netic field for the ferromagnetic cantilevered beam-plate are in excel lent agreement with their experimental data. By the way, the region of applicability to the Moon-Pao's model, or the couple model, is checke d by quantitative results.