관내법을 이용한 다층구조의 음향재료 음향성능 평가

Acoustical Property Evaluation of Multi-layered Material Using the Standing Wave Method

The acoustical properties of multi-layered treatments of materials used in applications, such as automotive liners, generally cannot be directly measured by a one-time test in a standing wave duct. Therefore, we have to consider predicting them by the four-pole transfer matrix method. This method requires performing TCM or TLM for measuring the transfer matrix of each layer and calculating the total transfer matrix of the whole multi-layered material. The final predicted absorption ratios and transmission losses of the multi-layered treatments strongly depend on the measured transfer matrix of each layer. All these functions have been included in a new designed acoustical software.