Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : March 09, 2017 -
In this study, we made the acoustic meta-materials. When sound pass a material having high density, it has the property that sound velocity becomes fast. We thought that it enables the inclination of the sound by using this property. Therefore, we devised acoustic meta-materials that keep a change of the density in it. At first, we devised the acoustic meta-materials of three pattern. First pattern is slit form. Second pattern is disposition of square prop. Third pattern is disposition of cross prop. We analyzed them using limited analysis software. It can analyze in two dimensions. In the analysis, three fields are made that the sound wave spread field, the field that incorporated acoustic meta-materials, the field that is after a sound passes it. The expression to give a sound wave is sin2π/λ(x-ct). λ is a wavelength, x is displacement, c is sound velocity. From the result of the analysis, we understood that the square prop affected the inclination of the sound most. Then, we made a 3D model. All the materials of the part are the acrylic. In future, we really produce it and going to test in the anechoic room.
