模态

The general infinite dimensional modal system describing liquid nonlinear sloshing is derived first by pressure integral variational principle. After selecting two dominating modes and three secondary modes based on the Narimanov-Moiseev third order asymptotic hypothesis, the infinite dimensional modal system is reduced to a five dimensional asymptotic modal system.

首先通过压力积分变分原理推导出描述液体作非线性晃动的一般形式无穷维模态系统，然后根据 Narimanov-Moiseev三阶渐近假设关系，通过选取二阶主模态和三阶次模态，将无穷维模态系统降为五维渐近模态系统。

Firstly, this paper investigated roundly the basic theory of the ambient vibration method, analyzed systematically the main methods of ambient vibration identification, and discussed their advantages and disadvantages. Then we established the finite element model of structural dynamics and test model and analyzed their mutual relation, improved MUSIC method and correlation function method in the harmonic identification, and gave the subspace method and correlation function method based on continuous model, which is multi-harmonic retrieve technique. And then, this paper also puts forward least-squares method to estimate directly structural physical and modal parameters; this approach replaced the derivative operator in the continuous time model with an equivalent approximation, and estimated the physical parameters of structures by the least-squares method. And then, we discussed the approximation methods of derivative and their convergence. Finally, this paper researched the modal parameters of a frame structure by the simulation and test. The results demonstrated that subspace method, correlation function method and the least-squares method are effective and stable respectively.

全面地研究环境振动识别方法的基本理论，系统地分析环境振动识别方法的主要方法，讨论它们的优点和不足；建立结(来源：6666AB44C论文网www.abclunwen.com)构动力学的有限元模型和试验模型，分析有限元模型与试验模型之间的相互关系；改进谐波识别中的MUSIC识别方法和相关函数识别方法，给出大型结构模态识别的连续型的子空间分解识别方法和相关函数识别方法，这个方法是多元谐波识别方法；提出直接识别结构的物理参数和模态参数的最小二乘方法，这个方法利用导数的近似值代替导数值，并运用最小二乘方法识别结构的物理参数，讨论导数近似值的选择方法，分析算法的收敛性；通过仿真计算和模型实验，研究高层框架结构的模态参数识别，验证子空间分解识别方法、相关函数识别方法和最小二乘识别方法的有效性，算法的稳定性；从理论和试验两个方面分析和研究噪声对识别精度的影响，影响识别精度的因素，以及部分模态成分的模态参数不能够被识别的原因。

In the second part, finite element model of the impeller of the centrifugal fan is built and the mode analysis is carried out.

第二部分建立了风机叶轮的有限元模型并进行模态分析，在ANSYS软件中，采用SHELL63单元对叶轮模型划分网格，进行前100阶模态分析，比较了叶轮自由模态和有预应力模态的差异，提取了模态参数。

Design in the design of the resin and the line type of the circuit board in the meantime, also all would resin of the fluxion mold 态 make an appropriate design and the consideration.

同时在树脂的设计和电路板的线型设计，也都会将树脂的流动模态作适当的设计和考虑。

According to the studied results at present, the studied objects are mainly thin plate and beam about sound radiation mode, a method computed sound radiation mode of complex structure is presented in this dissertation, according to the results of the previous two chapter, a theoretical method to solve acoustical radiation mode and acoustical radiation efficiency of complex structure by boundary element method and acoustical radiation theory is posed, the acoustical radiation power is expressed as a Hermitian quadratic form, while the radiation modes is determined by general eigenvalue decomposing, and then the radiation efficiency is computed via the orthodoxy of radiation modes with regard to impedance matrix and average velocity matrix; lastly, the validity of the method is proved by pulsating sphere and radiating cube with analytical results. According to results of the form three chapter, the structure sound radiation sensitivity is studied in detail, the sound radiation power of structure can be expressed as positive Hermitian quadratic form, the sound radiation sensitivity can be expressed as two parts by partial differential with respect to design variable, which are sensitivity of boundary velocity and impedance matrix, combined with the theory of FEM and BEM, the structure sound radiation can be translated to the analysis of structure dynamic sensitivity and impedance matrix sensitivity. The theory posted in this dissertation is tested by the FEM software ANSYS and the software AAS programmed by author.

在前几章的基础上，通过结构声辐射的模态理论对结构的声辐射的机理进行了深入地探讨，针对目前声辐射模态的研究对象主要是简单的板和梁类结构，提出了一种计算复杂结构声辐射模态的方法，利用前两章研究所得的结论，将边界元方法与广义特征值的理论结合起来研究了复杂结构的声辐射模态与声辐射效率，先将结构的声辐射功率表示为一个正定的厄米特二(来源：ABb7C论文0909网www.abclunwen.com)次型，运用广义特征值分解求解了复杂结构的声辐射模态，然后利用声辐射模态关于阻抗矩阵与均方速度耦合矩阵的正交性，求解了复杂结构的声辐射效率，最后用具有解析解的脉动球与辐射立方体验证了该方法的有效性。

The conclusion of this article contains:(1) The climatology symmetric index and antisymmetric index which represent the uniform system of ocean and atmosphere is defined according to the unique kinetic character of the large-scale fluid. The symmetric mode, a state mode, and antisymmetric mode, a propagate westward mode, of ocean and atmosphere are distinguished clearly from each other. Also, the primary part which determines the symmetric mode emerges from non-divergenct wind and the dominant part which contributes to the antisymmetric mode mostly is irrotational wind. The article also compares the disparity of the climatology distribution of SST and sea surface wind field between 1948-1975 and 1976-2005. The SST of both the tropical Indian Ocean and the tropical Pacific after 80's is warm than before 80's .

主要结论如下：(1)热带太平洋气候平均态所包含的海-气相互作用的资料分析根据海洋和大气的运动特性，定义了表征海洋大气系统的对称模态和反对称模态指数，通过两个指数对热带太平洋和印度洋关于赤道对称和反对称的两个模态进行区分，发现关于赤道反对称的海-气耦合模态主要包含了大气散度分量和海洋SST的相互作用；关于赤道对称的海-气耦合模态主要包含了大气旋度分量和海洋SST的相互作用，并从资料估算了该耦合模态向西传播的速度。

The security and perdurability of bridge are directly related to people's life and wealth, therefore a predicting and warning and timely maintaining system based on identifying the modal parameters and inspecting damages of the bridge structures is developed which can help to eliminate hidden troubles and avoid the occurrences of catastrophic accidents.

模态试验是桥梁结构竣工试验、健康监测等方面的重要组成部分，而模态试验分析的最终目标是识别出系统的模态参数，为桥梁结构的振动特性分析、健康监测等提供依据，因此，桥梁结构的模态参数识别是模态分析的重要内容。

The first part "On Physics" tries to analyze the cause and effect of measurement problems, including its philosophy as viewed from historism. It expounds the main thought which hides after deep physics on the standpoint of philosophy. It also reviews the new physical picture of this new theory.

上篇&物理学诠释&先用历史主义的观点剖析&测量难题&的来龙去脉及其带来的哲学问题，并简单介绍了由此引发的模态解释的背景和定义；再从哲学的视角阐述模态解释深层的物理学思想内核和理论框架；最后全面、整体地透视模态解释所勾勒出的新的量子图景，并在此基础上提出&模态是一种物理实在，概率是对模态的定量描述&的全新思想。

The first part "On Physics" tries to analyze the cause and effect of measurement problems, including its philosophy as viewed from historism. It expounds the main thought which hides after deep physics on the standpoint of philosophy. It also reviews the new physical picture of this new theory.

上篇&物理学诠释&先用历史主义的观点剖析&测量难题&的来龙去脉及其带来的哲学问题，并简单介绍了由此引发的模态解释的背景和定义；再从哲学的视角阐述模态解释深层的物理学思想内核和理论框架；最后全面、整体地****模态解释所勾勒出的新的量子图景，并在此基础上提出&模态是一种物理实在，概率是对模态的定量描述&的全新思想。

Based on the analysis for the lighter effect of substituting fixed interfacial modes with elastically constrained interfacial modes on results, the synthesis techniques using two typical substructural measured modes will be carried out easily due to its modes.

文中还进一步说明，用简化的弹性界面主模态代替固定界面约束主模态，对综合结果影响较少。这样，自由界面主模态和简化弹性约束主模态都很容易从模态试验中提取，因而子结构两类试验模态综合技术很容易实施。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。