多质量块声学超材料的隔声分析和减振研究

发布时间：2018-06-21 11:36

本文选题：声学超材料 + 低频隔声　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：声学超材料是近些年才得到发展的一种新型材料,有望广泛被应用于噪声控制减振隔振以及新型波导器件设计等领域。声学超材料的研究热点在于设计一种结构比较简单和制作成本较低的声学超材料,使其具有比较好的隔声和减振性能。本文从噪声控制和减振隔振两个方面出发,着重分析了声学超材料的低频隔声机理和在特定频段的减振特性,探讨了多质量块声学超材料在低频隔声减振隔振和弹性波控制方面的优势,结合实验验证有限元仿真结果,更好地将多质量块声学超材料推向实际应用中。首先,针对薄膜型声学超材料,引入含有阻尼力的等效质量弹簧模型证实了声学超材料在某些特定频率下具有负有效质量密度。以平面波传播理论为基础,利用有限单元法获得本文设计的薄膜型声学超材料胞元的隔声量曲线,结合本征模态分析和声固耦合分析获得薄膜型声学超材料的最佳隔声频率。通过改变质量块的几何参数、个数和分布形式使得薄膜型声学超材料的隔声波峰数目增多以及在低频段的隔声量大大增加。然后,借鉴二维声子晶体能带结构的求解方法,以薄板的Poisson理论为基础,通过平面波展开法获得声学超材料板的纵向振动能带结构方程。应用有限单元法获得二维声学超材料板的纵向振动频率响应曲线,验证能带结构图中的带隙,并详细探讨了声学超材料板在频率不同的纵向激励作用下的振动特征。通过改变多个散射体的分布形式设计了不同形式的声学超材料板,使其在减振隔振和弹性波控制方面表现优异。最后,为了验证声学超材料的隔声和减振性能,本课题根据仿真模型分别制备了薄膜型声学超材料胞元和二维声学超材料板。通过4206型阻抗管测试系统和振动测试平台进行隔声测试以及减振实验,获得声学超材料胞元的隔声曲线和二维声学超材料板在纵向激励作用下的频率响应曲线,与有限元仿真结果吻合较好。本文验证了所研究的声学超材料的隔声和减振特性。
[Abstract]:Acoustic supermaterial is a new material developed in recent years, which is expected to be widely used in noise control. Vibration absorption and isolation and new waveguide device design and other fields. The research focus of acoustic supermaterial is to design an acoustic supermaterial with simple structure and low cost to make it have better sound insulation and vibration absorption performance. In this paper, from the aspects of noise control and vibration isolation, the low frequency sound insulation mechanism of acoustic supermaterial and the characteristics of vibration absorption in specific frequency range are analyzed, and the low frequency sound insulation of multi-mass block acoustic supermaterial is discussed. The advantages of vibration absorption and vibration isolation and elastic wave control are combined with the experimental results to verify the finite element simulation results, and the multi-mass block acoustic supermaterial is better applied in practical application. Firstly, the equivalent mass spring model with damping force is introduced to confirm that the film acoustic supermaterial has negative effective mass density at certain frequencies. Based on the theory of plane wave propagation, the sound insulation curve of thin film acoustic supermaterial designed in this paper is obtained by using finite element method, and the optimum sound insulation frequency of thin film acoustic supermaterial is obtained by combining intrinsic mode analysis and acoustic structure coupling analysis. By changing the geometric parameters, number and distribution of mass blocks, the number of acoustic peaks of thin film acoustic supermaterials and the amount of sound insulation in low frequency band are greatly increased. Then, based on the Poisson theory of thin plate, the longitudinal vibrational band structure equation of acoustic supermaterial plate is obtained by using the method of two-dimensional phonon crystal energy band structure solution and the plane wave expansion method. By using finite element method, the longitudinal vibration frequency response curves of two-dimensional acoustic supermaterial plates are obtained, and the band gaps in the energy band structure are verified. The vibration characteristics of acoustic supermaterial plates under different longitudinal excitations with different frequencies are discussed in detail. By changing the distribution of multiple scatterers, different types of acoustic metamaterials are designed to perform well in vibration absorption and vibration isolation and elastic wave control. Finally, in order to verify the sound insulation and vibration absorption performance of acoustic metamaterials, thin film acoustic supermaterials and two-dimensional acoustic metamaterials were prepared according to the simulation model. The acoustic insulation curve of acoustic supermaterial cell and the frequency response curve of two-dimensional acoustic metamaterial plate under longitudinal excitation are obtained by means of sound insulation test and vibration absorption experiment of 4206 type impedance tube test system and vibration test platform. The results are in good agreement with the finite element simulation results. In this paper, the sound insulation and vibration absorption characteristics of the studied acoustic supermaterial are verified.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB39;TB535.1

【参考文献】