温度变化对一维声子晶体带隙的调控分析

The Influence of Temperature Changes on the Band Gap of One-dimensional Phonon Crystals

设计出基体材料为聚对苯二甲酸丁二醇酯(PBT),散射体材料为钛酸锶钡(BST)的一维声子晶体匀直杆.因为组成该结构的2种材料的弹性模量和泊松比都与温度相关,温度的改变将引起材料物理参数的变化,从而导致晶体中弹性波带隙结构的变化.采用集中质量法,仿真计算该声子晶体中温度分别为30℃和45℃情况下,2种结构的带隙分布情况,寻找相应的变化规律。研究表明:对于一维二组元BST/PBT匀直杆状声子晶体结构,随着结构温度由30℃增大为45℃,该声子晶体的第1带隙及第2带隙的起始频率、截止频率以及带隙的中心频率降低;同时,温度增大能够减小第1带隙的带隙宽度,增大第2带隙的带隙宽度。温度变化为调控声子晶体的带隙特性提供了新的设计思路。另外,基于温度变化还可以通过改变结构晶格常数的取值来获得所需的带隙.

Designing one-dimensional phonon crystal rods with Polybutylene Terephthalate （PBT） as substrate material and barium strontium titanate （BST） as scattering material is necessary because the structure of two kinds of material of elastic modulus and poisson＇s ratio is related to the temperature, and the change of temperature will cause the change of material physi- cal parameters, which can lead to the change of the elastic wave band gaps in the crystal structure. This paper makes simulation calculation of the band gap distribution of the two structures under the phononic crystal temperature 30 ~C and 45 ~C respective- ly to look for corresponding change rules using the concentration quality approach. The research has shown that stopping fre- quency and central frequency of the phonon crystal band gap 1 and 2 lower as the structure temperature rises from 30 ℃ to 45 ℃ for uniform straight rod phonic crystal structure of one-dimensional-and-2-group BST/PBT. Meanwhile, temperature rise can reduce band width of gap ＇1 and increase band width of gap 2. The realization of adjusting phononic crystal through the tem- perature changes provides a new design approach. Additionally, by changing the structure of the lattice constant values to a- chieve the desired band gap.