Free Transverse Vibration of Circular Plate of Stepped Thickness with General Boundary Conditions by an Improved Fourier–Ritz Method

Table 1

The first five natural frequencies with M and N increasing.

M and N	Modal number
	1	2	3	4	5
6	5.769	35.071	88.091	169.129	264.358
8	5.764	35.067	88.087	169.118	264.342
10	5.760	35.061	88.080	169.110	264.338
15	5.758	35.058	88.078	169.106	264.333
20	5.758	35.058	88.077	169.106	264.332
Xiang and Zhang [10]	5.75819	35.0577	88.07734	169.105	264.323
Avalos et al. [13]	5.82394	35.0578	89.6624	169.730	269.625