薄板声辐射的参数随机性研究与波传播方法
发布时间：2018-12-12 17:57
【摘要】：具有随机性结构的响应预测分析,近年来受到了很大的关注,在结构声振领域更是如此。在预测结构声辐射时,分析频域往往很宽,结构的声辐射对制造工艺误差会变得高度敏感,尤其在高频段。理想的情况是,这种敏感性能在设计阶段确定,以便确保生产设备的整体性能。本文以此为研究背景,针对结构噪声预示中的一个基本问题—薄板振动声辐射问题,研究薄板参数随机性对其声辐射的影响。 通过在薄板上随机布置质量点模拟薄板参数的随机性,采用Monte Carlo方法,开展薄板声辐射参数随机性研究。由于增加的随机质量点改变了结构的自振频率,为了避免每次求解结构的自振频率和模态,本文通过结构局部修改的方法,直接得到结构的声辐射,显著降低了随机声辐射分析的计算量。另外,传统基于模态叠加的声辐射预示方法,随着分析频率的增高,需要选取更多模态,从而增大了计算量。本文引入了辛空间波传播方法,只需选取少量的波形便可获得板的精确动力响应,而且适用于任意边界条件。 本文的主要内容包括如下几个方面： (1)采用传统的模态叠加法求解随机薄板声辐射问题。通过随机布置质量点考虑参数随机性,采用Monte Carlo方法进行随机声辐射分析。由于随机质量点附加到系统的质量阵中,在每次分析中需要重新求解结构的自振频率和模态,通过系统的稳态响应,进而分析随机薄板的声压分布。 (2)应用结构局部修改方法分析薄板随机声辐射问题。采用结构局部修改方法,从原系统响应出发,叠加修正项,得到新系统的稳态响应,进而求解随机薄板的直接声辐射问题。这种方法避免了每次求解结构的自振频率和模态,算例分析表明,这种方法与传统方法的计算精度相当,但显著降低了随机声辐射分析的计算量。 (3)采用辛空间波传播方法,研究薄板的直接声辐射问题。以四边简支板为例,得出简谐激励下薄板的稳态响应计算公式,并利用这些结果,进一步研究薄板向外辐射的声压。通过与传统基于模态叠加法的声压计算方法计算结果的对比,验证了辛空间波传播方法的有效性。
[Abstract]:In recent years, the response prediction analysis of random structures has attracted much attention, especially in the field of structural acoustic vibration. In the prediction of structural acoustic radiation, the frequency domain of analysis is very wide, and the structural acoustic radiation will become highly sensitive to the manufacturing process error, especially in the high frequency range. Ideally, this sensitivity can be determined at the design stage to ensure the overall performance of the production equipment. In this paper, the influence of the randomness of thin plate parameters on the acoustic radiation of thin plate vibration is studied, which is a basic problem in the prediction of structural noise. The randomness of sound radiation parameters of thin plates is studied by means of Monte Carlo method through random placement of mass points on thin plates. Because the increase of random mass point changes the natural vibration frequency of the structure, in order to avoid solving the natural vibration frequency and mode of the structure every time, the sound radiation of the structure is directly obtained by the method of local modification of the structure. The computational complexity of stochastic acoustic radiation analysis is significantly reduced. In addition, with the increase of analytical frequency, more modes need to be selected in the traditional prediction method of acoustic radiation based on modal superposition, thus increasing the computational complexity. In this paper, the symplectic spatial wave propagation method is introduced. The exact dynamic response of the plate can be obtained by selecting only a few waveforms, and it is suitable for arbitrary boundary conditions. The main contents of this paper are as follows: (1) the traditional modal superposition method is used to solve the acoustic radiation problem of stochastic thin plates. Considering the randomness of parameters, the random acoustic radiation analysis is carried out by Monte Carlo method. Because the random mass points are attached to the mass matrix of the system, the natural frequencies and modes of the structure need to be solved again in each analysis, and the sound pressure distribution of the stochastic thin plate is analyzed through the steady state response of the system. (2) the problem of random acoustic radiation of thin plate is analyzed by local modification method. Based on the response of the original system, the steady-state response of the new system is obtained by using the structural local modification method, and the direct acoustic radiation problem of the stochastic thin plate is solved. This method avoids each calculation of the natural frequency and modal of the structure. The numerical examples show that this method has the same accuracy as the traditional method, but the computational complexity of the stochastic acoustic radiation analysis is significantly reduced. (3) the direct acoustic radiation of thin plate is studied by symplectic spatial wave propagation method. Taking simply supported plates with four sides as an example, the formulas for calculating the steady response of thin plates under harmonic excitation are obtained, and the sound pressure of thin plates radiated out is further studied by using these results. The validity of the symplectic spatial wave propagation method is verified by comparing the calculated results with the traditional acoustic pressure calculation method based on modal superposition method.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB532
本文编号：2375036
[Abstract]:In recent years, the response prediction analysis of random structures has attracted much attention, especially in the field of structural acoustic vibration. In the prediction of structural acoustic radiation, the frequency domain of analysis is very wide, and the structural acoustic radiation will become highly sensitive to the manufacturing process error, especially in the high frequency range. Ideally, this sensitivity can be determined at the design stage to ensure the overall performance of the production equipment. In this paper, the influence of the randomness of thin plate parameters on the acoustic radiation of thin plate vibration is studied, which is a basic problem in the prediction of structural noise. The randomness of sound radiation parameters of thin plates is studied by means of Monte Carlo method through random placement of mass points on thin plates. Because the increase of random mass point changes the natural vibration frequency of the structure, in order to avoid solving the natural vibration frequency and mode of the structure every time, the sound radiation of the structure is directly obtained by the method of local modification of the structure. The computational complexity of stochastic acoustic radiation analysis is significantly reduced. In addition, with the increase of analytical frequency, more modes need to be selected in the traditional prediction method of acoustic radiation based on modal superposition, thus increasing the computational complexity. In this paper, the symplectic spatial wave propagation method is introduced. The exact dynamic response of the plate can be obtained by selecting only a few waveforms, and it is suitable for arbitrary boundary conditions. The main contents of this paper are as follows: (1) the traditional modal superposition method is used to solve the acoustic radiation problem of stochastic thin plates. Considering the randomness of parameters, the random acoustic radiation analysis is carried out by Monte Carlo method. Because the random mass points are attached to the mass matrix of the system, the natural frequencies and modes of the structure need to be solved again in each analysis, and the sound pressure distribution of the stochastic thin plate is analyzed through the steady state response of the system. (2) the problem of random acoustic radiation of thin plate is analyzed by local modification method. Based on the response of the original system, the steady-state response of the new system is obtained by using the structural local modification method, and the direct acoustic radiation problem of the stochastic thin plate is solved. This method avoids each calculation of the natural frequency and modal of the structure. The numerical examples show that this method has the same accuracy as the traditional method, but the computational complexity of the stochastic acoustic radiation analysis is significantly reduced. (3) the direct acoustic radiation of thin plate is studied by symplectic spatial wave propagation method. Taking simply supported plates with four sides as an example, the formulas for calculating the steady response of thin plates under harmonic excitation are obtained, and the sound pressure of thin plates radiated out is further studied by using these results. The validity of the symplectic spatial wave propagation method is verified by comparing the calculated results with the traditional acoustic pressure calculation method based on modal superposition method.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB532
【参考文献】
相关期刊论文 前7条
1 黄炎,刘大泉;弹性地基上的矩形薄板自由振动的一般解[J];国防科技大学学报;2001年03期
2 钟万勰;分离变量法与哈密尔顿体系[J];计算结构力学及其应用;1991年03期
3 石钟慈;;样条有限元[J];计算数学;1979年01期
4 梁健;张重超;;平板声辐射效率的级数表达式[J];上海交通大学学报;1990年03期
5 尹岗,陈花玲,陈天宁;薄板低频声辐射效率的研究[J];西安交通大学学报;1999年03期
6 沈崤,孙洪生;工程声学中的有限元法[J];声学学报;1981年04期
7 黎胜,赵德有;用有限元/边界元方法进行结构声辐射的模态分析[J];声学学报;2001年02期
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