基于侧面嵌入空气柱周期性结构薄板的隔声降噪研究

发布时间：2018-05-13 18:30

本文选题：周期性复合结构 + 禁带　；参考：《湖南大学》2013年硕士论文

【摘要】：振动与噪声广泛存在于建筑、机械、航空等各个领域中，抑制有害的振动与噪声就成为了工程技术中迫切需要解决的问题。作为传递振动的主要媒介—固体结构，其传播距离远，并且衰减较小，因此对固体结构的振动噪声控制是人们普遍关心的问题。采用周期性复合结构在振动噪声传递途径上对其进行隔离为这个问题的解决提供了新的思路。周期性复合结构具有弹性波或声波禁带，，即处于禁带频率范围内的弹性波或声波被禁止传播。因此，禁带处于实际的振动或者噪声频率范围内的周期性结构为现有工程实际中振动噪声问题的解决提供了一种新的可能。本文在讨论了周期性复合结构的现有基本理论和研究方法的基础上，研究了侧面嵌入空气柱周期性结构薄板的禁带特性和隔声降噪性能，探究其用于工程结构中振动噪声控制的可行性。主要研究内容包括： (1)利用平面波展开法和有限元法计算了侧面嵌入空气柱周期性结构薄板基本原胞的能带结构，并对计算结果进行比较分析。 (2)在基本原胞的基础上，对侧面嵌入空气柱周期性结构薄板的填充率等结构参数进行调制，研究了结构参数变化对禁带位置和宽度的影响。 (3)研究了无限周期和有限周期一维周期性结构的传播特性计算方法，并探讨了该型薄板用于隔声降噪的可行性。 (4)计算分析了有限长度侧面嵌入空气柱周期性结构薄板的传输特性曲线，讨论了周期数和填充率变化对隔声性能的影响，并通过薄板的位移场研究了结构参数对振动隔离的影响。结果表明，通过参数的合理调制和搭配，侧面嵌入空气柱周期性结构薄板能够调节禁带位置和增加衰减程度，达到良好的隔声降噪效果。
[Abstract]:Vibration and noise widely exist in the fields of building, machinery, aviation and so on. It is urgent to solve the problem of suppressing harmful vibration and noise in engineering technology. As the main medium of transmitting vibration, solid structure has long propagation distance and low attenuation. Therefore, the control of vibration and noise of solid structure is a common concern. Isolation of periodic composite structures from vibration and noise transmission provides a new way to solve this problem. Periodic composite structures have elastic wave or acoustic band gap, that is, elastic wave or acoustic wave in the range of band gap frequency is forbidden to propagate. Therefore, periodic structures with forbidden bands in the range of actual vibration or noise frequencies provide a new possibility for solving the problem of vibration and noise in existing engineering practice. On the basis of discussing the existing basic theory and research methods of periodic composite structure, this paper studies the characteristics of bandgap and sound insulation and noise reduction of the thin plate of periodic structure with side-embedded air column. The feasibility of its application in vibration and noise control of engineering structures is explored. The main research contents include: 1) the energy band structure of thin plate with periodic structure embedded in air column is calculated by using plane wave expansion method and finite element method, and the calculated results are compared and analyzed. 2) on the basis of the basic primitive cell, the structural parameters such as the filling ratio of the periodic structural thin plate embedded in the side air column are modulated, and the influence of the structural parameters on the position and width of the gap band is studied. The propagation characteristics of infinite periodic and finite periodic one-dimensional periodic structures are studied, and the feasibility of using this type of thin plate for acoustic noise reduction is discussed. In this paper, the propagation characteristic curve of thin plate with finite length side embedded air column is calculated and analyzed, and the influence of period number and filling rate on sound insulation is discussed. The effect of structural parameters on vibration isolation is studied by displacement field of thin plate. The results show that through the reasonable modulation and collocation of parameters, the lateral embedded periodic thin plate of air column can adjust the position of band gap and increase the attenuation degree, and achieve a good effect of sound insulation and noise reduction.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TB535

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