[1] S.S. Rao, V. Sundararajan, In-plane flexural vibrations of circular rings, (1969).
[2] J. Kirkhope, Simple frequency expression for the in‐plane vibration of thick circular rings, The Journal of the Acoustical Society of America, 59(1) (1976) 86-89.
[3] W. Kim, J. Chung, Free non-linear vibration of a rotating thin ring with the in-plane and out-of-plane motions, Journal of Sound and Vibration, 258(1) (2002) 167-178.
[4] A. Ellison, S. Yang, Natural frequencies of stators of small electric machines, in: Proceedings of the Institution of Electrical Engineers, IET, 1971, pp. 185-190.
[5] S.-C. Huang, W. Soedel, Effects of coriolis acceleration on the free and forced in-plane vibrations of rotating rings on elastic foundation, Journal of sound and vibration, 115(2) (1987) 253-274.
[6] Z. Khawly, D. Schramm, Analytical modal analysis for the stator system of a permanent magnet synchronous motor for hybrid vehicles and calculation of its natural frequencies, Proceedings of ISMA2010 Including USD2010, (2010) 4535-4548.
[7] M. Jin, Y. Wang, J. Pan, Vibration of circular rings coupled by elastic elements, Applied Acoustics, 148 (2019) 264-275.
[8] R. Yu, C. Mote Jr, Vibration and parametric excitation in asymmetric circular plates under moving loads, Journal of Sound and Vibration, 119(3) (1987) 409-427.
[9] Z. Li, S. Xue, Q. Ding, Preparation and Performance Test of Soldered Stators of Ultrasonic Motor, Journal of Testing and Evaluation, 45(3) (2017) 980-986.
[10] S. Wang, J. Xiu, S. Cao, J. Liu, Analytical treatment with rigid-elastic vibration of permanent magnet motors with expanding application to cyclically symmetric power-transmission systems, Journal of Vibration and Acoustics, 136(2) (2014).
[11] A. Rourke, S. McWilliam, C. Fox, Multi-mode trimming of imperfect thin rings using masses at pre-selected locations, Journal of sound and vibration, 256(2) (2002) 319-345.
[12] R.-C. Yu, C. Mote, Vibration of circular saws containing slots, Holz als Roh-und Werkstoff, 45(4) (1987) 155-160.
[13] M. Kim, J. Moon, J.A. Wickert, Spatial modulation of repeated vibration modes in rotationally periodic structures, J. Vib. Acoust., 122(1) (2000) 62-68.
[14] J. Chang, J. Wickert, Response of modulated doublet modes to travelling wave excitation, Journal of Sound and Vibration, 242(1) (2001) 69-83.
[15] J. Chang, J. Wickert, Measurement and analysis of modulated doublet mode response in mock bladed disks, in: International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, American Society of Mechanical Engineers, 2001, pp. 2239-2252.
[16] X. Wu, R.G. Parker, Vibration of rings on a general elastic foundation, Journal of Sound and Vibration, 295(1-2) (2006) 194-213.
[17] P. Bisegna, G. Caruso, Frequency split and vibration localization in imperfect rings, Journal of Sound and Vibration, 306(3-5) (2007) 691-711.
[18] S. Huang, W. Soedel, Response of rotating rings to harmonic and periodic loading and comparison with the inverted problem, Journal of Sound and Vibration, 118(2) (1987) 253-270.
[19] A. Metrikine, M. Tochilin, Steady-state vibrations of an elastic ring under a moving load, Journal of Sound and Vibration, 232(3) (2000) 511-524.
[20] S. Vangipuram Canchi, R.G. Parker, Parametric instability of a rotating circular ring with moving, time-varying springs, in: International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, 2007, pp. 809-822.
[21] W. Sun, S. Wang, Y. Xia, P. Zhang, Natural frequency splitting and principal instability of rotating cyclic ring structures, Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 232(1) (2018) 66-78.
[22] Z. Zhao, S. Wang, J. Yang, W. Chen, Parametric instability induced by traveling magnetic load within permanent magnet motors, Nonlinear Dynamics, 80(1-2) (2015) 827-843.
[23] Fourier transform, in: https: //en.wikipedia.org /wiki/ Fourier_transform. , 2020.