Host: The Japan Society of Mechanical Engineers
Name : Dynamics and Design Conference 2019
Date : August 27, 2019 - August 30, 2019
Create a microstructural model of a fiber-based sound absorbing material with a fiber diameter of 1μm or less using the finite element method, calculate the sound absorption coefficient and flow resistance by the homogenization method, and compare the results with the measured values. investigated. It is assumed that the microstructure model has a periodic microstructure, and the fiber orientation is 0°,90° using a parallel fiber model in which the fiber arrangement is uniform and a Suggard fiber model in which the fiber arrangement is shifted by half the interfiber distance. Assuming that the sound absorption coefficient and the flow resistance were calculated. From the results of sound absorption coefficient calculation, if the fiber diameter is 2μm or less, the frequency characteristics largely change depending on the fiber arrangement, and in the Suggard fiber model, the peak of the sound absorption coefficient appears smaller in frequency compared to the parallel fiber model. In the visual structure model, no significant change was found in the frequency characteristics. From the comparison of the measured values of the calculated values, the smaller the fiber diameter, the greater the divergence between the calculated frequency characteristics and the measured values. As compared with the parallel fiber model, the flow resistance of the sudgard fiber model is larger than that of the parallel fiber model. As a result of the calculated value and the measured value of flow resistance, the difference between the calculated value and the measured value was small regardless of the fiber diameter.
