Krasnozhon A. Development to theory of skin-effect in ferromagnetic bodies on base of WKB-method and Riccati equation

Object of research: ferromagnetic bodies and electromagnetic fields in them. The purpose of research: further development of the theory and methods for calculating the skin effect in ferromagnetic bodies by creating a new method of calculation of surface impedance. Methods of research: scientific aspects of the theory of electromagnetic fields, as well as various methods for solving differential equations and their systems. Theoretical and practical results: obtain a new universal approximation of the module and argument of absolute non-linear complex permeability of structural steel for the first harmonic; obtain a new universal approximation of the magnetization curves of electrical steel; a new methodology of calculation of surface impedance and specific losses in nonlinear ferromagnetic; first developed a methodology of calculation of surface impedance at high frequencies, taking into account the nonlinear magnetic characteristics of the medium; first showed that in magnetic materials at high frequencies the enlargement of the active component of the surface impedance tends to the maximum value of 1,8856; developed methodology of calculation of surface impedance and specific losses in nonlinear ferromagnetic medium is used to calculate the losses in the massive steel structures that are within range of an alternating magnetic field. Degree of introduction: are used in the Institute of electric welding NAS of Ukraine, in the educational process in the CSTU and are recommended for use in the Institute of electrodynamics NAS of Ukraine. Sphere of use: analytical study of skin-effect; calculation of losses arising in steel structures under the action of an alternating magnetic field; induction heating technology.