Electromagnetic forming by distributed forces in magnetic and nonmagnetic materials

• Published in: IEEE transactions on magnetics Vol. 40; no. 5; pp. 3319 - 3330
• Main Authors: Motoasca, T.E., Blok, H., Verweij, M.D., van den Berg, P.M.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.09.2004; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Conducting materials; Density; Dielectric constant; Elastic deformation; Elastodynamics; Electromagnetic fields; Electromagnetic forces; Electromagnetic forming; EMP radiation effects; Exact sciences and technology; Magnetic materials; Magnetic properties and materials; Magnetism; Mathematical analysis; Nonhomogeneous media; Permeability; Permittivity; Physics; Pulse shaping methods; Magnetic materials; Conducting magnetic materials; electromechanical forces; elastic field
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2004.834041

In this paper, we discuss the electromechanical force densities associated with pulsed electromagnetic fields in inhomogeneous, linear media with conductive losses, in the context of a process of shaping metal objects. We show that the conductivity and the gradients in permittivity and in permeability lead to volume forces, while jump discontinuities in permittivity and permeability lead to surface forces. These electromagnetic forces are assumed to act as volume (body) source densities in the elastodynamic equations and as surface source densities in the corresponding boundary conditions that govern the elastic motion of deformable matter. As an example, we apply the theory to the calculation of the elastic field in a hollow cylindrical object made of a conducting magnetic or nonmagnetic material. We compare the numerical results with those for the classical theory of elasticity with concentrated forces on the boundaries of the material as the source of the elastodynamic field.