【作者】 蔡阳生；

【导师】 吴硕贤；

【作者基本信息】 华南理工大学 ， 建筑技术科学， 2013， 博士

【摘要】 在测量建筑和建筑构件隔声量时，传统声压法存在无法判别漏声路径、受侧向传声影响较大、信噪比低以及低频准确度较低等缺点。声强法作为测量隔声量的另一可选方法，可克服上述缺点，有望为绿色建筑声环境评价提供更方便、更可靠的测量手段。本文从空气声隔声量的测量原理出发，对建筑和建筑构件的空气声隔声测量做了以下几方面的研究，具体包括：1．针对隔声测量对激发声源室声场的声源频率响应特性的要求，提出一种利用数字音频处理器对声源进行预均衡的技术，并通过实验证明该方法可得到较为平直的频率响应，满足隔声测量的要求。2．根据脉冲法测量隔声技术的原理,提出一种通过置换声源室和接收室的测量通道以修正通道响应不一致的方法,并设计实验方案进行验证。实验结果表明该方法在采用多通路测量系统时降低了对测量传声器及其放大设备的要求,在各测量通道的频率特性及灵敏度不一致时,仍可进行隔声测量并能得到可靠的结果。3．由于声压法和声强法在测量准确度上还存在一定的偏差，而且在不同实验室的偏差估计有所不同，因此我国有必要开展声强法测量空气声隔声量的准确度估计和偏差研究，为声强法测量国家标准提供数据支撑和实验验证。在同一实验室内对四个建筑构件分别采用声强法和声压法进行隔声量测量，并对实验结果进行了准确度估计和偏差原因分析。实验结果显示,声强法与声压法测得的隔声量在整个测量频率范围内基本一致,但在低频段个别频率上存在一定偏差。接收室的低频声场均匀度较差是造成这一偏差的主要原因。从房间模态密度出发，讨论了Waterhouse修正的缩略项和完整项在普通隔声室房间尺寸的差别，可以看出两者在低频范围的差别较大，并不能轻易忽略。因此若采用Waterhouse修正时，建议采用完整项修正。并指出在对声压法和声强法进行比较时，应将声压法的测量结果减去Waterhouse修正项，而非将声强法的测量结果加上Waterhouse修正项，会更符合隔声量的物理意义。4．通过对Gomperts矩形缝隙隔声量的计算，可以看出，在相同缝隙宽度时，在扩散场中处于中间位置的缝隙隔声量最大，在扩散场中处于边界位置的缝隙隔声量次之，平面入射声场中处于边界位置的缝隙隔声量最小。采用声强法对带有缝隙的门进行隔声量测量，并与理论值对比，可以看出理论值与实验值相符。证明了声强法现场测量隔声量的有效性，可为绿色建筑评价标准提供更好的测量依据。5.通过对建筑构件进行声强测量，绘出声强等值线图，可以发现隔声薄弱环节。但由于不同频段的声强等值线图体现出来的隔声薄弱环节可能会有所不同，因此在利用声强探测隔声的薄弱环节时，应结合不同段频的声强等值线图进行综合分析，可以更为准确地定位隔声薄弱环节,以便更有针对性地改善建筑和建筑构件的隔声性能。更多还原

【Abstract】 There are some deficiencies in the conventional sound pressure method measuringsound insulation in buildings and of building elements, such as being unable to identify thesound propagation path, being greatly affected by the flanking transmission sound, lowsignal-to-noise ratio and low precision in low frequency. Another sound insulationmeasurement method is based on sound intensity technique and overcome the aboveshortcomings. It is expected to provide easier and more reliable means of measurement toevaluate green building sound environment. In this dissertation, the measuring principle of theairborne sound reduction index is discussed and the measuring methods of sound reductionindex in buildings and of building elements are studied in details. The main researches arelisted as follows:1. The requirements of the response characteristic of measurement of sound insulation onthe spectrum of sound source in motivated sound field are analyzed, and then a newpre-equalization technique employing digital signal processor is introduced. Moreover, byexperiments, it is proved that the method can help to obtain a relatively flat frequencyresponse and meet the requirements of measuring sound insulation.2. Through an analysis on sound insulation evaluation technique using impulse methodwith multichannel system, a new method is proposed to correct the sensitivity differenceamong the channels by exchanging the channels in the sound source room and receivingroom.and then is applied to experiments to be testified. The results of the experiments showthat the channel-exchange method for correction can lower the requirements for themicrophone and pre-amplifier and able to achieve a reliable result when there is inconsistentsensitivity among the channels.3. There is still certain deviation in the precision estimation and bias of sound pressuremethod and sound intensity method. And the precision estimation and bias are different fromdifferent laboratories. Therefore, in order to prove data and experiment verification for themeasuring sound insulation in buildings and of building elements using sound intensity, it isnecessary to launch the study on the precision estimation and bias of airborne soundinsulation using sound intensity method in domestic laboratories. The sound insulations offour specimens are measured by the methods mentioned above in a laboratory and the resultof the experiments is analyzed to find out the causes of precision estimation and bias. The experiments show that these two methods have the same results in the whole frequency rangebasically, but still have some deviations in the specific low frequency band. It is pointed outthat the low-frequency deviations are caused mainly by the uniformity sound field ofreceiving room. From the perspective of modal density calculation, the size differencesbetween the abbreviated term and complete term of Waterhouse Correction in ordinary roomsize is discussed to find out the comparatively big difference of them in the low frequencyrange. Therefore, when applying the Waterhouse Correction, the complete term isrecommended. This dissertation also pointed out that the Waterhouse Correction term shouldbe subtracted from the results of the sound pressure method, instead of adding it to the resultsof the sound intensity method, so as to be more in line with the physical meaning of the soundreduction index, when the sound pressure method with the sound intensity method beingcompared.4．Through the calculation of the sound reduction index of Gompert’s rectangular slits,The sound reduction index of the same wide slits located at a partition edge is maximumwhere source room has a diffuse field. The second maximum is the slits at the middle of apartition where source room has a diffuse field. The minimum is the slits at the partition edgefor a normal incidence wave on it. The sound reduction index has been measured using soundintensity. In comparison, the experimental results are consistent with the theoretical value ofthe total sound reduction index. It is proved that the sound intensity method is effective inmeasuring the sound insulation in situ.5. The sound intensity contour can be plotted after measuring the building elementswith slits using sound intensity method. The weaknesses of sound insulation could be detected.However, there are the possible differences among the weaknesses of sound insulationindicated by the contours of the sound intensity in different frequency bands, ancomprehensive analysis on the index charts of the sound intensity in different frequencybands should be taken into consideration, when using the sound intensity method to detect theweaknesses of sound insulation, so as to determinate the sound leakages more accurately andimprove the sound insulation in building and of building elements in more targeted way.更多还原