查询词典 boundary element method

The quasi wavelets method introduce regularizer and make the scale function regularity and localization attributes. A meshless method and a quasi wavelets method based on the natural boundary integral equation in this paper are presented. Corresponding formulas are developed for the implementation of the present method.

本文提出的自然边界元的无网格方法是将无网格方法与自然边界元方法相结合，使其不仅具有自然边界元的降维及计算便捷、稳定等优点，而且还具有无网格方法的只需节点信息、不必划分网格、后处理方便等优点，这使该方法在处理高维问题上计算简捷。

3D-CTM (Coupled Thermo-Mechanical Forming Simulation) software for precision forging process of aero-engine blade was developed. The key technologies of 3D coupled rigid-viscoplastic thermo-mechanical FEM simulation of blade forging process were studied systematically. By using the remeshing method of contracting from the boundary to the inner, new mesh system from old distorted mesh system can be obtained. A method of modifying the position of nodes touching on the die according to its original normal was proposed to avoid "dead lock" problem due to uncontinuity of normal of scatted die meshes. The pseudo-static iterative algorithm was used to simplify the coupled thermo-mechanical computation. In particular, formulations to determine relaxation factor β was established for rigid viscoplastic FEM adopting penalty function method, and an improved cubic factor rapid algorithm derived from these formulations was proposed by combining with the advantage of advance and retreat search method.

采用基于边界构形的内缩法，实现了三维畸变网格的重新划分；提出了初矢修正法对触模节点的位置进行修正，解决了由于离散的模具网格的法矢不连续造成的&死锁&问题；采用准静态迭代法简化了速度场和温度场耦合计算过程；特别是针对减速因子β的选取，建立了适用于三维复杂成形过程刚粘塑性罚函数法有限元三次因子法的计算公式，并结合进退搜索法提出了改进的三次因子快速算法，提高了模拟计算效率和稳定性，在此基础之上，开发了面向叶片精锻过程的三维刚粘塑性热力耦合有限元模拟分析系统(3D-CTM)，系统的可靠性得到了圆柱体镦粗的验证。

The technique of boundary-fitted coordinate system is used to overcome the difficulties resulting from the complicated shapes of natural river boundaries;the method of alternating direction implicit finite difference scheme is used to solve the partial differential equations in the transformed plane;and the technique of moving boundary is used to deal with the river bed exposed to water surface.

用适体坐标技术克服天然河道复杂的几何边界给有限差分法所带来的困难；用交替方向隐式有限差分格式求解变换平面上的偏微分方程；用动边界技术处理河床的淹露。

In this paper,the author discusses the multi-layer solution with two special limits in boundary layer of the singularly perturly boundary value problem and obtains uniformly valid zero order asymptotic expansion by using the matching asymptotic expanding method.

利用匹配渐近展开法，讨论了奇摄动边值问题中边界层内存在有两个特异极限的多层解，得出了奇摄动边值问题的一致有效的零次渐近展开

In Chapter 1, two solutions to the elliptical boundary value problem have been constructed through a monotone iterative process, and they might be identical. In Chapter 2, the author expresses the local solution to the parabolic initial boundary value problem taking advantage of Green function. In Chapter 3, the asymptotic solution to the initial value problem of Duffing equation is obtained and the method for finding the approximate solution to the inverse problem is put forward.This paper is planned with a view to the author's research means.

从研究结果看：第一章通过单调迭代过程构造出椭圆型方程的边值问题的两个解，并且指出二者可能是同一个解；第二章利用格林函数给出了抛物型方程的初边值问题的局部解的解析表达式；第三章中，先对Duffing方程的初值问题写出解的渐近展开式，再对其反问题提出一种求近似解的方法。

In this thesis, we provide a simpler form of the axisymmetric boundary integral equation, and modify some aspects of the direct boundary integral method.

本论文给出了轴对称情形下边界积分方程的一个更简单的形式，并在若干方面改进了直接的边界积分算法。

For the purpose of extending the applicability of the coupling method to the bidimensional exterior steady Oseen problem, we will introduce a smooth artificial boundary separating an interior inhomogeneous region from an exterior homogeneous region .The solution in the exterior region is represented by an integral equation over the artificial boundary.

为了将这种耦合方法应用于二维外部定常的Oseen问题，我们人为的引入一条光滑的边界，将内部非均匀区域和外部均匀区域分离，外部区域的解可以由人工边界上的积分方程来描述，此积分方程同内部区域的速度-压力变分形式结合为耦合变分形式，我们则可以使用有限元的方法求解此耦合变分方程。

In Part I, the biharmonic equation are chosen, and the boundary peanlty finite method using piecewise cubic Hermite elements is used to seek their approximate solutions, in particular satisfying the derivative and periodical boundary conditions.

在第一部份里，选择使用片断三次 Hermite元素的边界惩型有限元素法来求解满足边界导数条件和边界周期条件的重调和方程式的近似解。

The theory of complex variable function for anisotropy plate combined with boundary collocation method is applied to calculation pin-loads and contact region as well as the contact stress on the hole boundary.

采用各向异性板的复变函数理论和边界配置方法，对连接件进行分区，加以限制条件，对多钉连接的复合材料层合板的钉载和板与螺栓间的接触应力和接触区域进行了计算。

Based on the analysis of the characteristics of the compensation directions for boundary curve s in rapid prototyping direct slicing, a new method, which can determinate the compensation direction by converting the boundary curve to beeline polygon,is proposed.

在分析快速成型制造中直接切片真实边界曲线补偿方向特点的基础上，提出了一种将曲线边界转化为直线多边形进行补偿方向判定的方法，并阐述了该判定方法的几何意义。

Molecular Distillation is a kind of high vacuum distillation method, which is suitable for the separation of high boiling, heat sensitivity and viscidity products.

分子蒸馏技术是一种在高真空条件下进行的连续蒸馏过程，适合于分离高沸点、热敏性及具有生物活性的混合物。

They are to the Noughties what yuppies were to the Eighties .

那在六十年代是时髦的，但在八十年代肯定是过时了