【摘要】 运用FDTD(时域有限差分法)研究了弹性波/声波通过二维正方形排列的铁/水声子晶体的传播特性.发现铁/水声子晶体在高频范围存在完全带隙,软包层铁/水声子晶体在低频范围出现共振带隙,它们分别对应于不同的带隙形成机理.通过铁/水声子晶体和软包层铁/水声子晶体的组合,可以得到从高频到低频的组合宽带隙结构,从而达到在更宽频范围内控制弹性波传播的目的;而且通过调整包层的厚度、铁芯的大小、以及填充率等结构参数,可以有效地调节组合宽带隙的频率结构.更多还原

【Abstract】 Using FDTD method, the characteristics of elastic/acoustic wave propagating in two dimensional phononic crystals (PCs) consisting of Fe square arrayed cylinders in water was investigated. The absolute band gap was found in high frequency range for Fe/water structure, and the resonance gap was found in low frequency range for coated Fe/water structure, where the Fe cylinders were softly coated by rubber. These two gaps correspond to different mechanisms. Constructed with these two kinds of PCs, a combined wide gap from high to low frequency can be achieved, so the elastic wave propagating can be prohibited in a wide frequency range. Furthermore, the combined wide band gap can be adjusted effectively through changing the structure parameters, such as the size of Fe core, thickness of coating layer, filling ratio etc.更多还原