本研究利用兩種不同的薄膜材料來組成四種薄膜型聲學超常材料，針對300 ~4000 Hz頻率區間，藉由多重物理分析軟體(COMSOL Multiphysics)模擬基本聲學結構後，配合薄膜平均位移圖來了解隔音機制與基本特性後，探討使用兩種不同疏密度的井字框架下，改變薄膜密度、薄膜半徑、張力與兩層薄膜的間距等參數，對聲學結構的隔音效果影響。接下來，在實驗方面，利用聲學阻抗管配合三麥克風校正法進行薄膜/鋁框架之三明治結構以及薄膜/井字框架之三明治結構的實驗量測，透過不同疏密度的井字框架、薄膜材料以及結構厚度來調查對聲學結構的穿透損失影響，最後除了比較兩個類型聲學結構的差異外，也與模擬結果進行比較，探討不同與原因。
從結果來看，透過改變薄膜密度、半徑、張力與薄膜間距可以明顯地影響到聲學結構的隔音效果，且當井字框架加入後，藉由減少薄膜自由振動的面積，並將其切割為許多小區塊，使穿透損失值有一定程度的提升。而使用較密的框架時，也會得到較好的穿透損失值。在最後的比較部分，雖然穿透損失曲線趨勢接近，不過在使用密框架時，實驗結果與模擬有明顯差距，可能為人工誤差以及在阻抗管內的空氣損耗所導致。而實驗上高低起伏的峰谷值也無法在模擬中看見，這點仍需要在做探討。

In this study, we use two different membrane material to compose four membrane-type acoustic metamaterials. Aiming at the frequency range of 300~4000 Hz, basic acoustic structures are simulated with COMSOL Multiphysics, and using average displacement graph of membrane to understand the insulation mechanism and properties. Then, we will discuss the influence of parameters such as membrane density, membrane radius, tension, and the distance between two layers of membranes on the insulation effect of acoustic structure with two different densities tic tac toe frames. Next, in the experiment aspect, we use two different sandwich structures to do this experimental measurement that investigated the effect of sound transmission loss in structure with different parameters like densities, membrane materials, and structure thicknesses by acoustic impedance tube and three microphones calibration method. In the last section, we compare the difference between the two types of acoustic structure and compare the experiment result with simulation to know difference and reason, too.
From the result, the sound insulation effect can be significantly affected by changing membrane densities, radius, tension, and distance between two layers of membranes, and when the tic-tac-toe frame is added, the sound transmission loss can be increased by reducing the free vibration area of membrane and cutting the membrane into many pieces. When using the dense frame, the better sound transmission loss value will also be obtained. In the last comparison section, although the curve trends of sound transmission loss are close in experimental result and simulation, there is a significant difference when using the dense frame, that may be caused by artificial errors and air loss in the impedance tube. And, the peaks and valleys values of the experimental result can’t be seen in the simulation, which still needs to be explored.

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