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

Figure 5

Variation of first six natural frequencies of an elliptical plate (a/b = 2) with respect to the size of cut-out. (a) Thickness (h/b = 0.2). (b) Thickness (h/b = 0.4). (c) Thickness (h/b = 0.6).

(a)

(b)

(c)