Research Article
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 |
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