The accuracy of the nodal patterns of combined degenerate mode shapes for a square membrane by previous researchers is investigated, and the nodal patterns of superimposed degenerate modes for square and non-square membranes and simply-supported plates are presented in a full range of amplitude ratios.
BolotinVVMakarovBPMishenkovGVShveikoYY (1960) Asymptotic Method of Investigating the Natural Frequency Spectrum of Elastic PlatesVol. 6. Moscow: Raschet na Prochnost, Mashgiz, pp. 231–253. [In Russian].
2.
CourantRHilbertD (1962) Methods of Mathematical PhysicsVol. I. New York: Interscience Publishers, pp. 302–302.
3.
Leissa AW and Qatu MS (2011) Vibrations of Continuous System. New York: McGraw Hill.
4.
NadaiA (1925) Die Elastiche Platten, Berlin: Julius Springer, pp. 164–185.
