一维声子晶体的振动特性研究

THE ELASTIC WAVE BAND GAPS OF ONE DIMENSIONAL PHONONIC CRYSTAL

利用平面波展开法计算了6种不同材料组分的一维杆状结构声子晶体振动带隙,分别讨论了晶格的尺寸大小、两种复合材料的组分比以及材料的密度等对声子晶体振动带隙频宽的影响.结果表明:在晶体的晶格尺寸大小、两种复合材料(金属和非金属)的组分比不变的情况下,振动的第一带隙的初始频率随着金属密度的增大而减小,截止频率基本不变;当所选材料的组分比不变时,随着晶格尺寸的增大,一维二组元复合声子晶体的振动带隙的初始频率及截止频率减小,同时带隙的频宽也随之减小;而当材料组分比小于1时即所选金属材料的份数小于非金属时,随着金属材料量的增大,振动带隙的初始频率及截止频率减小,从而带隙的频宽也减小;而当材料组分比大于1时即金属材料的份数大于非金属时,振动带隙的初始频率增大,截止频率减小,以及带隙的频宽也随之减小.

With Plane Wave Expansion （PWE） method, the elastic wave band gaps of one dimensional phononic crystal were investigated. The influences of lattice constant, volume fraction and density of the material on band gaps are discussed in this paper. When lattice constant and volume fraction are stable, with the increase of the density of materials, the beginning frequency of the first band gap decreases and the end frequency changes little; When the materials are same, with the increase of lattice constant, both the beginning and the end frequency of the first band gap decrease and the range of the gap decreases, too; When the volume fraction is less than 1, with the increase of the volume fraction, the beginning and the end frequency of the band gap decrease, at the same time, the range of the band gap decreases; When the volume fraction is larger than 1, the beginning frequency of the band gap increases and the end frequency of the band gap decreases and the range of the band gap decreases.