【作者】 袁骥轩；

【导师】 黄其柏；

【作者基本信息】 华中科技大学 ， 机械设计及理论， 2010， 博士

【摘要】 空腔内部噪声问题是一个具有极强实际意义的问题,其应用对象包括汽车驾驶室、飞机和舰船的船舱。虽然随着技术的发展,空腔内部的噪声水平已有了很大的改善,但依然有很多负面评价,这种反映就涉及到空腔声品质问题。声品质是用户(乘客)对封闭空腔系统内声场噪声接受度的心理感觉反映。它包括响度、粗糙度、波动度等一系列参数,并以不同的感受影响着人类的听觉心理。空腔声品质设计研究对低噪声空腔设计具有重要的理论意义和使用价值,对解决其他工程问题也有广阔的应用前景。本文运用以解析为主、结合数值计算的方法,对简谐力激励下多弹性板边界耦合的结构-声学空腔内部声场及声品质特性进行了研究。基于阻抗-导纳逼近理论,建立了边界条件均为简支的力激励时的结构-声学耦合空腔内的声场模型；结合Zwicker响度模型,建立了结构-声学耦合系统内声场响度预测模型,利用数值计算的结果分析了空腔中三个不同位置点的响度分布规律,通过计入人类听觉对频率的选择性接收特性,分析了空间位置对声强级、声强密度以及特征频带声强级的影响,为声固耦合空腔内声响度预测和设计提供了解析模型；并推导了空腔中含有吸声材料的声学边界条件声场模型。对于空腔内声场内的声音,用0-20Hz调制音对其调制时,会产生独立处理的声品质参数：波动度。运用Green函数法建立了多激励力多弹性面响应的声场模型,并利用修正的声波动度模型,建立了结构-声学耦合系统的波动度的解析计算模型,并揭示了调制频率、阻尼率以及耦合板模态密度等对声波动度的影响规律,为耦合空腔内声波动度设计提供了预测方法。当调制音频率增大到20-300Hz时,会产生另外一个可独立处理的声品质参数：粗糙度。利用有限元法和修正后的声粗糙度模型,给出了复杂形状腔体结构-声学耦合系统内声场的粗糙度模型。揭示了调制音频率、调制音声压级以及耦合板刚度对声粗糙度的影响规律,为复杂形状结构-声学耦合系统内声场的粗糙度的预测和控制提供了方法。本文还对声品质主观评价方法进行了研究。针对评价者在使用语义细分法评价时,对其评价结果优劣的判断需要凭经验的问题,将灰色区间的概念引入语义细分法,提出了自己的判断准则。针对成对比较法耗时耗力,并容易导致评价者疲劳而使评价失效的情况,提出了一种新的关于声品质多维度属性的主观评价方法——与标准比较法。组织10人评价组对某9个声样本进行了评价试验,利用多元线性回归分析,建立用以心理声学客观参数量化描述主观评价结果的声品质数学模型,并进行了检验。利用一个矩形结构-声学耦合系统,通过试验对耦合腔体内的响度预测方法进行了验证。更多还原

【Abstract】 It is very practical and meaningful to study the noise problem inside a cavity, whose application objects include driving cabs of automobile, passenger compartments of a plane and cabins of a ship. With the development of technology, although the noise level in cavity has been improved, many negative reactions still exist, which are caused by the problem of "sound quality in cavity". Sound quality includes a series of parameters, such as loudness, fluctuation strength and roughness, etc. These parameters influence the human hearing sensation in different ways. The research on sound quality in cavity has theoretical meaning and good use value for low noise and high performance cavity design. This study also has wide application prospect on other engineering problems.Analytical method is the main method used in this dissertation. Integrated with numerical method, this dissertation makes a profound research on the characteristics of interior acoustic field and sound quality in structural-acoustic coupled cavity under different boundary conditions. Based on the theory of impedance and mobility, the interior acoustic field model is established for the structural-acoustic coupled system under simply supported conditions, and combined with the Zwicker’s loudness model, a model of interior acoustic field sound loudness, which is also in the structural-acoustic coupled system, is established for forecasting. and the model of the cavity interior acoustic field whose acoustic boundary condition contains sound absorption material is derived. The sound loudness distribution of three different location points in the cavity is analyzed by using the numerical calculation results. The effect of spatial position on sound intensity level, sound intensity density and critical-band level is also studied throuth taking the frequency selectivity of human hearing system into account. And the research results provide analytical method for forecasting and designing sound loudness in the structural-acoustic coupling cavity.An independent parameter-sound fluctuation strength appears when the interior sound of structural-acoustic coupling cavity is modulated by other sounds whose frequency is between 0 to 20 Hz. Using Green Function Method and modified fluctuation strength model, a new calculation model of fluctuation strength in the structural-acoustic coupling cavity is established. The effects of modulation frequency, damping ratio and the coupling plate modal density on the sound fluctuation strength are revealed. The numerical results are presented to provide forecasting method for fluctuation strength design in structural-acoustic coupled cavity.Another independent parameter-sound roughness appears when the sound is modulated by other sounds whose frequency is between 20-300 Hz. Using finite element method and modified sound roughness model, the model of sound roughness in complexly-shaped structural-acoustic coupling cavity is established. The effects of modulation frequency, modulated sound pressure level and the coupling plate stiffness on the sound roughness are revealed. The method for forecasting and controlling the acoustic roughness in the complexly-shaped cavity is presented.Subjective evaluation method of sound quality is also studied in this dissertation. Aiming at the problem that when the jury evaluates by using semantic differential method, the judgment of the evaluation results usually depend on experience, the application of grey interval is introduced to semantic differential method, and a new judgment criterion is put forward. Compared with the time-consuming paired comparison method which would lead to failure of the evaluation, a new subjective evaluation method-comparison method with criteria, which can reflect multidimensional attributions of sound quality, is established. An experiment to evaluate nine acoustic samples participated by a 10-person jury is held. A mathematic model of sound quality is established and tested to describe subjective evaluation result in quantity with psychoacoustic parameters by using multiple linear regression method.The proposed prediction model of loudness of structural-acoustic coupled cavity is examined by a rectangle cavity samples.更多还原