方柱转动情况下二维声子晶体的声波带隙结构

Acoustic band gaps of two-dimensional phononic crystal with rotating square rods

用平面波展开法研究方形钨柱在环氧树脂基体中呈正方形排列和三角形排列时的带隙以及方柱转动对带隙结构的影响。研究结果表明:在相同的填充率下,钨柱按三角形排列比按正方形排列更容易具有较宽的完全带隙;在任意的填充率下,当钨柱按正方形排列时,系统的最低完全带隙相对宽度随着转动角度的增加而变窄;当按三角形排列时,系统的最低完全带隙相对宽度随着转动角度的增加先变宽,后变窄;插入体的填充率越高,方柱转动对系统带隙的影响越大。

By the plane-wave expansion method, the acoustic elastic band structures of twodimensional phononic crystal composed of square or triangle array of tungsten square rods embed ded in epoxy, and the influence of rods rotating on the acoustic band structures were studied. The results show that the lowest complete band gaps in the triangle array are wider than those in the square array at the same filling fraction. For the square array, the normalized gap width of the lowest complete band gap decreases monotonously with the increase of rotation angle at certain filling fraction, and for the triangle array, it enlarges at a lower angle and then narrows at a higher angle with the increase of rotation angle. The higher the filling fraction, the stronger the influence of rod rotating on band gap.