【作者】 宋爱玲； 陈天宁； 王小鹏；

【Author】 Song Ai-ling;Chen Tian-ning;Wang Xiao-peng;State Key Laboratory for Strength and Vibration of Mechanical Structures,Xi’AN Jiao Tong University;

【机构】 机械结构强度与振动国家重点实验室西安交通大学；

【摘要】 为了分析晶格滑移对声子晶体板能带结构的影响,根据有限元法和Bloch定理,利用Comsol软件对一维U-T形声子晶体板发生x方向和y方向晶格滑移时的能带结构进行了计算和分析。通过分析布里渊区中心点和边界点的位移场分布,对晶格滑移调节能带结构的物理机理进行讨论。本文提出的这种新型一维U-T形声子晶体板,与常规一维声子晶体板相比,在中低频范围内具有更低频更宽的禁带,可以拓宽声子晶体在中低频减振降噪领域的应用范围。研究发现,沿x方向和y方向的晶格滑移均可很大程度地调节能带结构,打开了一些新的禁带;能带变化图和模态分析表明,晶格滑移会影响Lamb波模式转化,导致相邻能带发生分离或耦合,进而打开新禁带或关闭原来的禁带。晶格滑移对能带结构的特定调节作用为声子晶体应用于工程领域提供了一定的理论基础,也为声子晶体能带结构调节提供了一种有效的方法。更多还原

【Abstract】 In order to investigate the effect of crystal gliding on the band structures of one-dimensional U-T shape phononic crystal plates(1-D U-T PCs), the band structures of the 1-D U-T PCs with crystal gliding both in x and y direction are calculated and analyzed theoretically by using Comsol software based on finite element method and Bloch theory. Physical mechanism of gliding effects on band structures is also studied with displacement fields of points located at Brillouin center and edge. Compared with the conventional one-dimensional phononic crystal plates, the novel 1-D U-T PCs presented in this paper have lower and wider band gaps in low frequency range which can enlarge the application of phononic crystals in engineering field. Numerical results show that the crystal gliding both in x and y direction can significantly modulate the band structures and opens some new gaps; Band structures evolution and eigenmodes indicate that crystal gliding can influence the Lamb wave mode conversion leading to separations or interactions of adjacent bands to open new band gaps or close original gaps. The gliding effect on the band structures provides theoretical basis for phononic crystals applied to engineering field and an effective way to modulate the band structures.更多还原