声子晶体中低频减振降噪技术及带隙特性研究

Study on medium-low frequency vibration and noise reduction technology and bandgap characteristics of phononic crystal

声子晶体作为由多种材料复合而成的人工晶体结构,具有小尺寸、特定频段减振降噪可设计的特点,在近年来成为机械装备减振降噪研究新热点.声子晶体减振、降噪能力与带隙水平有着重要联系.故提出了一款包覆魔方型声子晶体结构,并介绍包覆魔方型声子晶体的组成结构;分析了声子晶体带隙特性的影响因素,分别从材料、晶格常数、散射体尺寸等因素对声子晶体带隙特性展开分析.为了进一步确定包覆魔方型声子晶体完全带隙特性,验证声子晶体减振降噪能力,基于包覆魔方型声子晶体单胞,设计声子晶体板,搭建传输损耗求解模型,对声子晶体传输损耗进行分析.此外引入缺陷态声子晶体概念,考虑散射体尺寸缺陷和散射体材料缺陷,对声子晶体传输损耗能力进行优化.

Phononic crystal,as an artificial crystal structure composed of a variety of materials,has the characteristics of small size,vibration reduction in a specific frequency band,and noise reduction can be designed.The vibration and noise reduction capabilities of phononic crystals have an important relationship with the band gap level.Therefore,first of all,the designed structure of the coated Rubik′s cube phononic crystal is proposed,and the composition structure of the coated Rubik′s cube phononic crystal is introduced;secondly,the influencing factors of the band gap characteristics of the phononic crystal are analyzed.Factors such as size are used to analyze the band gap characteristics of phononic crystals.In order to further determine the complete band gap characteristics of the coated Rubik′s cube phononic crystal and verify the vibration and noise reduction capabilities of the phononic crystal,based on the coated Rubik′s cube phononic crystal unit cell,a phononic crystal plate was designed,and a transmission loss solution model was built.Phononic crystal transmission loss analysis.In addition,the concept of defect state phononic crystal is introduced,considering the size defect of the scatterer and the material defect of the scatterer,to optimize the transmission loss capability of the phononic crystal.