A generalized variational principle and theoretical model for magnetoelastic interaction of ferromagnetic bodies

The quantitative analysis shows that no theoretical model for 3-d magnetoel astic bodies, in literatures to date, can commonly simulate two kinds of di stinct experimental phenomena on magnetoelastic interaction of ferromagneti c structures. This makes it difficult to effectively discribe the magnetoel astic mechanical behavior of structures with complex geometry, such as shel ls. Therefore, it is a key step for simulating magnetoelastic mechanical ch aracteristics of structures with complex geometry to establish a 3-d model which also can commonly characterize the two distinct experimental phenomen a. A theoretical model for three dimension magnetizable elastic bodies, whi ch is commonly suitable for the two kinds of experimental phenomena on magn etoelastic interaction of ferromagnetic plates, is presented by the variati onal principle for the total energy functional of the coupling system of th e 3-d ferromagnetic bodies. It is found that for the case of linear isotrop ic magnetic materials, the magnetic forces obtained by this model include n ot only the body magnetic force which is the same as that got from the magn etic dipole model, but also a distribution of the magnetic traction on the surface of the magnetizable body. iind the value of the traction is equal t o the jumping one of the Faraday electromagnetic stress on the two sides of the surface, which does not appear in any model, such as magnetic dipole m odel and axiomatic model.