含内部连接体的二维声子晶体弹性波宽频带隙特性

声子晶体的弹性波带隙特性使得它在开发用于减振降噪的新型功能材料方面具有广阔应用前景。为获得宽频大带隙,改进了一种含连接体的正方晶格声子晶体结构.利用有限元法计算并分析了不同结构配置下其能带特性和振动模态。数值结果表明,单胞中同时引入新的质量块以及连接体将对原连接体的自由振动模态产生抑制作用,可在原分离的两带隙频率范围内获得相对带宽超过100%的单一宽频带隙。此外,通过调整几何尺寸、连接体数目、结构对称性等参数可进一步调控结构带隙特性。 

Properties of large elastic wave bandgaps in two-dimensional phononic crystals with internal connectors

Phononic crystals with elastic wave bandgap properties have found broad application in the development of new functional material for vibration isolation and noise suppression. A kind of phononic crystal structure in square lattice with connectors is improved to obtain a wide frequency bandgap. The bandgap properties and the vibration mode of the phononic crystals in different structural configurations are simulated and analyzed using the finite element method. The numerical results show that the improved structures display a single wide frequency bandgap with the relative bandgap width more than 100% within the frequency range of initial separated bandgaps. The reason fbr the occurrence of the single bandgap is the suppression of the free vibration mode of original connectors, resulting from the simultaneous introduction of the mass and connectors in unit cell. Moreover, the bandgap properties can be manipulated by changing the geometry size, the number of connectors and the symmetry of the structure.