Method for acquisition of orthotropic material parameters and calculation of modal frequencies in permanent magnet synchronous motor

This article presents a novel method for fastly obtaining orthotropic material parameters in permanent magnet synchronous motor. First, a theoretical model of the equivalent single cylindrical shell is introduced with three orthotropic material parameters by considering the orthotropic characteristics of the motor. Then, the relationship of three orthotropic material parameters and the axial mode order m, the radial mode order n and modal frequency f is established. On this basis, an analytical method with m = 0 is proposed to acquire three values, and its adaptability is pointed out. Meanwhile, based on the above obtained orthotropic material parameters, the calculation method of modal frequencies is presented. Finally, the modal test and finite‐element method are implemented to verify the rationality of the proposed method. In this paper, the assembly of the enclosure, stator core, windings and end covers is equivalent to a single cylindrical shell, and this orthotropic characteristics are considered. Then, an analytical method is proposed to fastly obtain the orthotropic material parameters. On this basis, different modal frequencies are calculated.