Analysis and Synthesis of Plane-Parallel Magnetic Fields of Actuators with Shape Memory Effect by Combined Finite Element and Point Magnetic Moment Method

Abstract

The article is devoted to solving the actual problem of analysis and synthesis of actuators based on ferromagnetic shape memory alloy. A combined method of calculating plane-parallel magnetic fields of actuators has been developed: in a linear environment the method of point magnetic moments is used, in a non-linear environment the method of finite elements is used. Application of vector magnetic points allows reducing the dimensionality of the field calculation problem. The number of unknowns, compared with the finite element method, decreases by about 18 times with a relative error in calculating the magnetic flux density of less than 2 %. On the basis of the method, an algorithm has been developed to solve the inverse problem of determining the magnetomotive force of the magnetizing coils of the actuator taking into account the dependence of the magnetic properties of ferromagnetic shape memory alloy on its deformation and the effect on the deformation of the material of the external load. Algorithm provides considerable reduction of calculation time with required accuracy of magnetic field parameters determination. This allows us to effectively solve the problems of synthesizing actuators, to analyze malfunctions and predict their condition in real time. The proposed combined method can be used for calculating the magnetic fields of other electrical devices.