含谐振单元和弹性支承谐振单元的声子晶体低频禁带特性研究

在结构中周期性地添加谐振单元可以构造局域共振声子晶体并产生低频禁带。本文提出了一种具有谐振单元和弹性支承谐振单元的声子晶体结构,通过声子晶体理论和振动理论对该结构的禁带特性和禁带调控特性进行了计算与分析。结果表明,该结构可在0 Hz处形成禁带;禁带内对振动的衰减强度由衰减因子和有限结构周期数共同决定;结构中存在1条可调控禁带和3条不可调禁带;可调控禁带可以通过改变谐振单元和弹性支承谐振单元的结构参数加以调控;不可调禁带包括第一禁带,它们能够较为稳定地对一定频率的弹性波产生衰减作用。该结构所具有的禁带特性在管路、桥梁和汽车减振领域具有潜在应用。

Low-Frequency Band Gap Characteristics of Phononic Crystal of One-Resonator and One-Resonator with Elastic Support

Local resonance phononic crystals can be constructed by adding resonance elements periodically, and low frequency band gap can be generated. In this paper, a phononic crystal composed of one-resonator and one-resonator with elastic support has been presented. The band gap characteristics and band gap regulation characteristics of the structure were calculated and analyzed by using phononic crystal theory and vibration theory. The results show that the initial frequency of the first band gap is 0 Hz. The attenuation of vibration in the band gap is determined by the attenuation factor and period number of the finite structure. There are one tunable band gap and three untunable band gaps in such structure. By changing the structural parameters of one-resonator and one-resonator with elastic support, the tunable band gap can be tuned. The untuable band gaps which include the first band gap can attenuate elastic wave stably. The band gap characteristics of the structure have potential applications in the field of vibration reduction of pipelines, bridges and automobiles.