查询词典 BEM

Differing from the general BEM that is attributed from the general boundary integral equation, The natural boundary element method attributed from the natural BIE has not only the advantage of the dimensionality, but is confirmed and gain the only NBIE from the original problem.

无网格方法仅仅需要节点信息，克服了有限元等传统数值方法对网格有较强依赖性的缺点，摆脱了网格的束缚，避免了大量的网格分划、复杂的网格生成及重新划分的工作，减少了因网格畸变而引起的困难，而且收敛快、精度高、易于实现和进行后处理工作。

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。

To provide theory foundation for inverted deduction work, numerical simulation for propagating in highway-surface with exceptional block and inanition and crack has been performed. The numerical simulation results show that the BEM is an effective method for the elastic-waves propagating in highway-surface concrete medium.

利用边界元法能够很好的描述弹性波在砼介质中传播的特性，正演模拟异常石块、脱空和裂缝对波的传播的影响，为进一步的反演工作提供理论依据。

The hydration force is determined by the boundary elementary method, which includes the Coulombic interactions between the charged solute atoms with the induced surface charge and surface pressure of solvent.

水化力通过BEM求出，包括溶质分子与表面诱导电荷的库仑相互作用和溶剂对分子表面的压力。

Considering the effect of load and helical angle on the instaneous width of contact area, this paper uses the BEM program for calculating the deformations at different place along the width of convex tooth and concave tooth of W-N gear and gets the relevant deformation curves.

并首次应用三维边界元方法，在计入齿面瞬时接触迹宽度随外载、螺旋角而变化的条件下，计算了双圆弧齿轮凸齿面端部和凹齿面端部的变形。

A set of analytical integral method of triangular element linear interpolation BEM has systematically been deduced and put forward.

提出并系统推导了一套三角形线性插值边界元的解析积分公式。

Sound transmission through submerged, fluid filled elastic thin shell excited by incident acoustic waves in the interior domain was calculated using the coupled FEM and BEM method.

利用耦合有限元与边界元方法计算了声波激励下浸没在无界流场中内部充满流体的弹性薄壳声透射。

Using the Mindlin theory, the four-node finite element shell modal of healthy and damaged structure is formed; Using Green Function theory, the fluid around the structure is considered to be inviscid, irrotational and incompressible, and then the effect of fluid to structure is translated to the added mass matrix compared with global mass matrix using BEM.

基于Mindlin理论，本文建立了描述健康和损伤的四结点有限元板壳单元模型；基于Green函数理论，将结构所处的流体环境考虑为无粘、无旋、不可压缩的理想流体，推导了三维问题拉普拉斯方程的基本解，并利用边界元方法将流体对结构的影响归结为对结构整体质量矩阵的影响；针对各向同性损伤单元，采取刚度各向整体弱化的方法分析；对于各向异性损伤单元，采用Kachanov理论，引入了x和y两个方向的弹性损伤折减系数。

Second,the preliminary informations include the conditions that the potentials in the corrosion system should satisfy and the BEM basic formulas of Laplace equation are also discussed.

其次，预备知识包括腐蚀系统所满足的控制方程及边界条件和Laplace方程的边界元基本公式的推导。

The interactions between gas and particles were considered by a two-way coupling method.The motion of particles in the spouted bed with complex geometry was solved by combining DEM and boundary element method.The minimal spoute...

通过采用BEM+DEM-CFD相结合的方法进行模拟计算，得到了喷动床的最小喷动速度，研究了不同表观气速下床内的流型，得到了二维导流管喷动床的床层压降与表观气速的关系，统计分析了喷射区、环隙区内颗粒的运动速度和相应的空隙率，全面地描述了二维导流管喷动床内的气固流动特征。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。