[Retracted] Free Vibration Analysis of Thick Rectangular and Elliptical Plates with Concentric Cut-Out

Table 5

Frequency parameter of a square plate with a cut-out thickness of h = 0.2.

Present method	1.718	1.8355	2.324	5137.428 (rad/sec)
Ref. [18]	1.716	1.8345	2.323	—
Ref. [6]	—	—	—	5136.5 (rad/sec)
% error	0.11%	0.054%	0.043%	0.02%