摘要
从两种材料组成的一维杆状声子晶体的振动方程出发,给出无限周期结构的振动波色散关系和半无限周期结构表面波色散关系。发现带隙宽度、表面波频率均与材料组份比有关。对于具有自由表面的声子晶体,当自由表面层材料的速度小于另外一种材料速度时,存在表面局域态。利用有限元法,仿真了有限结构声子晶体的振动频率响应。当存在表面局域态时,振动频率响应在带隙频率范围内出现共振峰,这些共振峰至少减小了声子晶体20dB的减振效果。
Based on the vibrational equation of the one-dimensional thin rod phononic crystals composed of two kind of material, the vibrational wave and surface wave implicit dispersion relation in periodically layered infinite and semi-infinite media are provided. The width of band gaps and surface wave frequency both relate with the material portion ratio. For the phononic crystals with a free surface, the necessary condition for the existence of the surface localized modes in the free surface is found to be the velocity of the material with free surface less than that of the other material. Using the finite element method, the vibrational frequency response of finite-size phononic crystals and found the particular resonance peak due to the surface localized modes in the band gaps is calculated. These resonance peaks decreae the frequency response attenuation at least 20 dB.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2005年第6期35-38,共4页
Journal of Mechanical Engineering
基金
国家973重大基础研究资助项目(51307)。
关键词
声子晶体
振动带隙
表面局域态
Phononic crystals Vibration band gap Surface localized modes
