查询词典 boundary element method

In this paper, from two aspects of the total potential method and abnormal potential, three types of boundary conditions which affect calculating results in the finite element method are analyzed, and this provides a foundation for using the appropriate boundary conditions and selecting the best distance to enhance its accuracy.

本文从总电位法和异常电位法两个方面，分别就直流电法有限元中所采用的三类边界条件对计算结果的影响进行了分析，为采用合适的边界条件及选取最佳边界距离来提高正演精度提供了基础。

Element-free Galerkin Method is a effective method for solving partial differential equations with the help of shape functions coming from moving least squares approximation. It is well-suited to problems involving large deformation and crack propagation etc on which Finite Element Method can not be used easily. But EFGM is computationally expensive and it is hard to impose the essential boundary condition. Coupling the EFGM and FEM can fetch up the defect of EFGM and improve the efficiency highly.

无网格伽辽金法是基于移动最小二乘法的一种用来求解偏微分方程非常有效的方法，在处理诸如高度大变形、裂纹动态扩展等有限元法较难解决的问题时有其独特的优势，但是存在处理边界条件复杂，计算量大的不足，将无网格法同有限元耦合可以解决这些缺点，极大的提高计算效率。

Based on wave propagating in three directions of elastic foundation, vibrating displacement could be assumed to be in three forms along three directions. Hooke's law and theory of waves were adopted to deduce the formula of coupled viscous boundary. The coupled viscous boundary could be applied in finite element method.

根据波在地基的3个方向都可以进行传播的特点，假定了地基中质点沿3个方向的振动表达式，通过胡克定律和波动理论，推导了弹性地基中三维动力问题的耦合粘性边界的公式。

Based on coupled heat transfer theory and finite element method , outer boundary conditions between parts were transformed into inner boundary conditions of the component

基于耦合传热理论和有限元方法，将零件间的外边界条件转变为零件的内边界条件，直接对零件进行耦合仿真计算。

Secondly, point out that meshless method is different from finite element method in handling boundary condition and numerical integral because the approximation function of meshless method is not inserted function, it have itself special methods. Deduces meshless Galerkin essential equation of parabolic partial differential equation with the method ofweighted residuals------Galerkin. Furthermore, discusses the main factors which may effectthe calculation precision and give some suggestion with which can get the best result.

其次，由于无网格法的近似函数不是插值函数，所以无网格Galerkin法在处理边界条件和对区域积分时是不同于有限元的，它有其独特的处理方法，从加权残量法——Galerkin出发，推导出抛物型偏微分方程无网格Galerkin法的基本方程，并对影响无网格Galerkin法的主要因素进行探讨，给出了取得最佳效果的相应建议。

Formula. At the same time, the article raised the seismic reduction factor formula for the SSDI system.The paper adopts finite element method based on the ANSYS procedure, and realizes the simulation of soil constitutional relationship through choosing Davidenkov soil model with proper parameters and using restartup method in ANSYS. Then, the procedure makes the soil nonlinearity simulation come true byusing parameter design language of APDL. Element Combin14 is be used to simulate viscoelastic boundary and radiation damping effect. At the same time, it presents integrated damping matrix for considering the coupling of different damping of soil and structure.

文章以ANSYS为计算分析工具和平台，通过对Davidenkov地基模型的研究及其参数的选取，利用ANSYS的重新启动分析方法并采用APDL参数设计语言来编制程序，实现对土体非线性动力本构模型的模拟；同时利用ANSYS中Combin14单元模拟粘弹性边界，以此建立人工边界来模拟辐射阻尼效应；并提出集成阻尼矩阵的方法，解决结构和地基土阻尼不同而导致的阻尼耦合的问题。

The book covers one-, two- and three dimensional problems which are solved by using exact and approximate analytical methods and numerical methods such as: the finite difference method, the finite volume method, the finite element method and the boundary method.

书中涵盖一，二和三是利用精确和近似分析方法和数值方法，如：有限差分法求解二维问题，有限体积法，有限元法和边界法。

After comparing with many techniques available for dealing with the open boundary problems, the asymptotic boundary conditions combined with the finite element method are employed for the calculation of 3-D open boundary magnetic fields in ironless PM motor.

根据对各种开域电磁场计算方法的分析比较，本文将渐近边界条件法和有限元法结合解决无铁心永磁电机三维开域磁场计算问题。

An optimum design for the complex body formed together with the volute casing, base ring and cement foundation of a hydraulic turbine is made by the gradient method and a program is developed on the basis of finite element analysis with the plane and shell element, body element, boundary element and pseudo element.

本文对由水轮机蜗壳、座环和水泥基础所构成的复杂组合体，在采用板壳元、块体元、边界元和伪单元等四类单元进行有限元分析的基础上，选用最速下降法研究了优化设计过程，并编制成程序系统。

In this dissertation the"Penalty"finite element method was employed to compute the velocity of the three-dimensional flow of power-law fluid in a profile die. In order to decrease the needed computer memory and raise the stability of numerical simulation, a set of decoupled methods such as PFEM, pseudo-body force method and transformation of momentum equation to the elliptic equation was developed to establish the general finite element equations to compute the distributions of velocity and viscoelastic stress of the three-dimensional viscoelastic flow of the Phan ThienTanner fluid in a profile die. During numerical simulation of the extrudate swell of the PTT fluid, the flow in the die and out of the die was analyzed separately, which demands less computer memory. The key techniques used in numerical simulation of the three-dimensional extrusion from dies such as decision of boundary conditions, creation of initial velocity field, selection of penalty factor, high Weissenberg number problem , regeneration of the free surface were studied in detail.

中文题名聚合物异型材口模挤出三维流动研究副题名外文题名 Study on three-dimensional flow of polymer melts during the process of profile extrusion from dies 论文作者涂志刚导师柳和生包忠诩教授学科专业材料加工工程研究领域\研究方向学位级别博士学位授予单位南昌大学学位授予日期2001 论文页码总数148页关键词挤出成型聚合物材料挤出口模聚合物异型材馆藏号BSLW /2003 /TQ320 /9 本文建立了求解挤出口模内幂律流体流动速度场的通用三维罚有限元模型；对于非线性粘弹性的Phan Thien-Tanner流体，为了降低模拟计算对计算机硬件的要求，并使模拟计算更加稳定，采用了一种去耦算法，包括罚有限元方法、拟体力方法和动量方程的椭圆类方程转化方法，并建立了求解速度场和粘弹性应力场的总体有限元方程；对于PTT流体的挤出胀大问题，提出了挤出胀大熔体口模内外分离模拟法，这样可以显著降低数值模拟对计算机硬件的要求。

I'm strongly against the death penalty — it's an eye for an eye.

我不赞成死刑——这是以牙还牙的报复行为。

And to get you the support you need, we're enlisting all elements of our national power: our diplomacy and development, our economic might and our moral suasion, so that you and the rest of our military do not bear the burden of our security alone.

并给你们所须的支援，我们正徵召国家所有各种的力量：我们的外交及发展，我们的经济力量与道德劝说，所以你们与其他军人不须要孤独地负起国家安全的责任。