铁尾矿砂复合板的非柱形孔吸隔声性能研究

发布时间：2018-02-13 15:58

本文关键词： 多孔材料吸声系数隔声量非柱形孔铁尾矿砂　出处：《南昌航空大学》2017年硕士论文　论文类型：学位论文

【摘要】：由于工业、交通运输业的迅速发展和城镇化的推进,噪声污染日益严重,尤其是在人口密集、经济发达的大中城市,特别在高速公路、铁路两旁周边区域,成为环境治理中备受关注的热点问题。同时,迅猛发展的高层建筑对隔墙的轻质高强度和减少容积率占用提出了更高的要求,因此,薄而轻质的建筑用吸隔声材料的研发已经成为环境噪声控制领域的前沿研究热点。研制多孔复合吸音和隔音材料已经成为了新型降噪环境功能材料发展的一个趋势,对提高高层建筑住房的容积率和减少承重有重大意义。多孔结构是实现材料轻质的有效途径且能有效吸声但其隔声量很低,而采用密度高的基体材料来制备多孔材料可同时提高其隔声性能,因此本文尝试将铁矿尾矿砂作为中空板材的填料形成多孔夹芯层,以其为研究对象,探讨非柱形孔的吸隔声分析计算方法和参数影响规律。铁矿尾矿砂大量的堆积废弃已经给人们的生态环境带来了许多的破坏,本文的研究有助于找到高效合理的铁矿尾矿砂的再资源化利用新途径。本文首先借助Biot理论重新整理了柱形孔结构的理论计算模型。由于非柱形孔可以视为切割成许多层不同孔径的近似柱形孔串联而成,且其总传递矩阵等于各层传递矩阵依次相乘;基于此构想,本文巧妙推导建立了球台形孔多孔板声传递矩阵的理论计算公式。运用Matlab软件平台编制了球台形孔多孔板声传递矩阵的专用的数值模拟计算程序,探讨了减少近似误差的球台形孔的最优切片层数,通过对球台形孔多孔板孔径、声波频率、厚度以及孔心距的改变,得到了其参数对吸声系数和隔声量的影响规律,这些规律能够为今后多孔复合结构的吸隔声材料的设计提供参考和依据。在数值模拟的基础上,本文利用现代3D打印制备技术,制备了多孔板厚度为20mm的由球台形孔组成的多孔材料试件,通过实验测试结果,验证了本文建立的球台形孔传递矩阵理论计算公式的正确性。最后,借鉴球台形孔理论计算方法构建的思路,推广使用到不规则孔的传递矩阵构建上,对填充尾矿砂构成的不规则孔作了初步探讨,并对填充尾矿砂多孔材料的隔声性能进行了实验测试,为今后进一步研究奠定了基础。本文得出的一些重要结果如下:(1)根据本文建立的球台形孔传递矩阵理论计算公式得到的数值模拟结果与相应实验测试结果较吻合,该球台形孔的传递矩阵可以用于球台形多孔声学材料的设计计算,且其构建思路可推广到不规则孔的理论研究中。(2)利用本文借助Matlab软件所编制的球台形孔传递矩阵理论计算程序发现在任意孔径下球形孔的吸声系数都是随着切片层数的增加而增大并且慢慢趋于稳定,因此本文从趋于稳定的区间中寻找出既满足计算精度的要求又能降低由于切片层数的增加而增加Matlab计算软件的计算负担的最优切片层数。并由此发现了可利用求出的切片层数与球形孔孔径的关系得出的规律,为各形孔和不规则孔的吸隔声设计计算提供参考。(3)对于单层球形孔,吸声系数和隔声量均随孔径的增大而降低;在相同孔径下,随孔层数的增加吸声系数和隔声量在增大;在孔层数相同时,孔径越小吸声系数和隔声量越大。在球形孔层数相同时,吸声系数和隔声量随着球心距的增大而增大。(4)将铁尾矿砂颗粒假设为标准的球型,利用球台形孔的多孔材料得出的结论和切片的思想,对铁尾矿砂颗粒多孔材料进行理论计算和实验测试,对比结果发现具有很好的一致性。(5)将本文的理论推广应用于不规则孔隙(如裂缝)中,结果可行。有进一步深入研究的价值。
[Abstract]:As the industry, transportation industry and the rapid development of urbanization, the noise pollution is becoming increasingly serious, especially in the densely populated and economically developed large and medium-sized city, especially in highway, railway on both sides of the surrounding area, has become a hot issue of concern in environmental governance. At the same time, the rapid development of the high-rise building on the wall with light weight and high strength reducing the volume occupied and put forward higher requirements, therefore, thin and lightweight building R & D sound-absorbing material has become a research hotspot in the field of cutting-edge environmental noise control. The research and development of porous composite sound absorption and sound insulation materials has become a trend in the development of new functional materials for environmental noise, increase the volume of high-rise building housing and reducing the rate of bearing is of great significance. The porous structure is an effective way to realize the lightweight materials and effective absorption but the loss is very low, but with high density The matrix material to prepare porous materials can improve the insulation performance, so this paper attempts to iron ore tailings as hollow plate filler to form a porous core layer, takes it as the research object, to explore the non cylindrical hole of the sound absorption of calculation methods and parameters. A large number of iron ore tailings sand accumulation has brought many the damage to the ecological environment of the abandoned people, new ways of utilization of resource, this research helps to find reasonable and efficient iron ore tailings sand. Firstly, using Biot theory to rearrange the cylindrical pore structure theory calculation model. Due to the non cylindrical hole can be regarded as approximate cylindrical holes cut into many layers in series different aperture formed, and the overall transfer matrix of each layer in turn is equal to the transfer matrix multiplication; based on the concept, this paper established the table cleverly shaped hole porous plate acoustic transmission matrix theory calculation formula The special type. The numerical table shaped hole perforated transfer matrix simulation program is written by Matlab software platform, discusses the optimal slice reduced table shaped hole approximation error, based on the table shaped hole aperture of porous plate, acoustic frequency, thickness and Kong Xinju change, got the influence of parameters on sound absorption coefficient and impedance, these rules can for the future of porous composite absorption structure to provide reference and basis for the design of sound insulation materials. On the basis of numerical simulation, this paper by using the technique of modern 3D printing system, porous materials preparation of porous plate thickness of 20mm are composed by table shaped hole specimens, through the experimental test the results verify the correctness of the established table shaped hole transfer matrix theory formula. Finally, using table shaped hole theory calculation method of construction, to promote the use of irregular holes The transfer matrix construction, the irregular hole filling tailings structure are discussed, and on the sound insulation performance of the tailings filling porous materials are tested, and laid the foundation for further research. Some important results of this paper are as follows: (1) according to the established numerical table shaped hole transfer matrix the theoretical calculation formula of the simulation results are in good agreement with the corresponding experimental results, the table shaped hole transfer matrix can be used to calculate the design table shaped porous acoustic material, study and its construction method can be applied to irregular hole theory. (2) the use of the table form the Matlab software hole transfer the theory of matrix calculation program found the absorption coefficient of spherical pores in any aperture are increased with the increasing number of slices and gradually stabilized, the stable region in To find out the optimal slice number can meet the requirements of accuracy and can reduce the computational burden due to the increased number of sections increased Matlab calculation software. It showed that the relationship can be obtained by slicing layers and the pore of the law, provide the reference for the design of sound absorption is calculated for each hole and irregular holes (3). For the single-layer spherical hole, absorption coefficient and impedance with pore size decreases; in the same aperture, with the increase of absorption coefficient and impedance in the increase in the number of holes; hole layers are the same, the smaller aperture absorption coefficient and impedance increases. In the same number of spherical pores, absorption coefficient and impedance increases with the increase of the sphere center distance. (4) the iron ore tailings as the standard spherical particle hypothesis, using table shaped hole porous material, the conclusion and the strip theory of iron tailing sand particle porous material The results of theoretical calculation and experimental tests show that the results are in good agreement. (5) the application of this theory to irregular pores (such as cracks) is feasible and has the value of further research.

【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU973;TU112

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