| Summary: | 碩士 === 國立成功大學 === 土木工程學系碩博士班 === 100 === Here, a commercial finite element package ABAQUS with different types of elements was used to numerically analyze the sound transmission losses of foamed inorganic polymers. It is found that solid element can effectively simulate the transmission loss of a solid plate while acoustic medium with a volumetric drag can effectively simulate the low-frequency acoustic response of a foamed inorganic polymer. In addition, three types of models were employed to investigate the sound insulation of foamed inorganic polymers with different microstructures: (a) a closed-cell microstructure with a single cell size; (b) a closed-cell microstructure with different cell sizes; (c) a closed-cell microstructure with tunnels. Furthermore, foamed inorganic polymer specimens with three different pore-size distributions were produced and tested to measure their sound transmission losses. Experimental results indicate that the variation of sound transmission losses is insignificant if the porosity and surface density of foamed inorganic polymers are the same. Also, numerical results suggest that the effect of microstructural geometry on the sound transmission losses of foamed inorganic polymers with the same surface density is negligible, consistent with the experimental results. Therefore, the proposed 2D numerical model can be utilized to partially replace tedious experimental works when experimental cost and consuming-time are concerned.
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