Free Vibration of Rectangular Plates with Porosity Distributions under Complex Boundary Constraints

Table 9

Nondimensional frequency parameter Ω of porous rectangular plates with different porosity coefficients (h/b = 0.2 and a/b = 0.5).

Type	Mode no.	Porosity coefficients
		0.1	0.2	0.3	0.4	0.5	0.6	0.7
I	1	0.6342	0.6238	0.6128	0.6011	0.5886	0.5751	0.5603
	2	0.7886	0.7756	0.7619	0.7473	0.7316	0.7146	0.6959
	3	0.9876	0.9708	0.9535	0.9357	0.9176	0.8995	0.8822
	4	1.0266	1.0097	0.9918	0.9728	0.9524	0.9305	0.9065
	5	1.2109	1.1906	1.1691	1.1462	1.1217	1.0954	1.0671
II	1	0.6367	0.6292	0.6216	0.6140	0.6067	0.5999	0.5943
	2	0.7917	0.7823	0.7729	0.7635	0.7544	0.7459	0.7389
	3	0.9876	0.9709	0.9539	0.9365	0.9189	0.9017	0.8858
	4	1.0304	1.0178	1.0051	0.9924	0.9800	0.9683	0.9586
	5	1.2141	1.1977	1.1810	1.1642	1.1476	1.1318	1.1180
III	1	0.6334	0.6220	0.6097	0.5961	0.5809	0.5637	0.5435
	2	0.7877	0.7735	0.7581	0.7412	0.7224	0.7010	0.6758
	3	0.9873	0.9695	0.9502	0.9291	0.9055	0.8786	0.8472
	4	1.0256	1.0071	0.9870	0.9650	0.9405	0.9127	0.8799
	5	1.2099	1.1882	1.1645	1.1386	1.1097	1.0768	1.0382