查询词典 boundary element method

This thesis consists of two parts. The first one was that boundary value problem was discrete with five point difference method. Three kinds of memory formats were studied, which were full matrix, half band width and row compress sparse. Full matrix memory format and half band width memory format first was contrasted. The results show that half band width has efficiency in space. Then the algebraic system of finite element method was solved by Gauss-Seidel iteration method to popular row compress sparse memory format.

本论文由两部分组成，第1部分针对边值问题，用5点差分格式进行离散，并对离散矩阵这类大型稀疏矩阵，研究了系数矩阵的3种存储格式的优劣，即：满矩阵存储格式、半带宽存储格式和按行压缩稀疏存储格式，首先我们将满矩阵存储方式和半带宽存储格式进行了对比，迭代法的数值实验表明：利用半带宽存储的矩阵在空间运算方面具有高效性；然后针对目前数值实验中流行的按行压缩稀疏存储格式，实现了有限元离散代数系统的迭代法的求解。

Many typical problems are studied and compared with boundary collocation method, traditional finite element method and analytical methods. The results indicate that the method is accurate and simple for stress intensity factor computation and is easy to be used in practical engineering.

文中作了大量的裂纹应力强度因子计算，与边界配置法、传统有限元法以及解析法进行了系统的比较，结果表明该方法用于应力强度因子计算不但精度较高，而且简便易行，便于工程实际应用。

Compared with Finite Element Method and Finite Difference Method, Boundary Integral Equation Method is computationally more efficient.

与有限元法和有限差分法相比，该方法具有更高的计算效率。

However,authors still do not find the relevant references on convergence and symmetric problems of the semi-analytical solution.Based on the semi-analytical solution for Hamilton canonical equation theory,the formulations of the clamp and simply supported and symmetric boundary conditions on the Hamiltonian element are derived by the variational principle.Several numerical examples show that with increase of meshes,the convergence rate of the semi-analytical solution is faster than the convergent rate of traditional finite element method based on displacement.

①在厚度上没有任何位移和应力模式的假设，由于传递矩阵方法的引入，从理论上讲，不受板壳厚度或层合板壳层数的限制；②采用弹性力学的Hamilton正则方程半解析法，可以克服边界的局部化效应[8]；③由于在平面内或圆柱壳的曲面内采用了有限元法，所以一般的板壳问题不受结构侧面边界条件的限制，在复杂工程板壳问题上具有广泛的应用领域。

Through comparison with finite element method, it has been demonstrated that boundary clement method is an effective method in the analysis of some complicatedly loaded parts and local stress concentration areas on loaders.

通过与有限元法比较表明，边界元法是分析装载机某些受力复杂零件和局部应力集中区域的有效分析工具。

In quasi-static conditions, the closed expressions far from source in the air and the earth is derived for electric dipole source, and by using it as the outer boundary conditions of the finite element method, difficulties in loading the boundary conditions is solved.

在准静态近似条件下，分别推导了水平电偶极子在空中和大地的远区电场闭合表达式，并以此作为有限元计算中的外边界条件，解决了边界条件加载的困难。

The new schemes hold the main advantages of the DG finite element method: the method can easily handle complicated geometries and the boundary conditions; the method is highly parallelizable.

格式保持了DG有限元方法的优点：易处理复杂的几何区域和边界条件，具有高度的并行性。

Some concepts about the reliability are described, and the method for calculating the reliability of system is provided by making linear substitution. While taking Stochastic Finite Element Method into the reliability calculation, a Nonlinear SFEM model is founded, and methods to resolve some problems in SFEM calculation are given. So as to the calculation of the force boundary, a method in FEM is provided for sabot pressure calculation, base of this, the numerical calculation model is carried out.

给出了弹丸发射强度可靠性计算中的一些理论和概念；给出了串联系统可靠性的逐步线性等效计算方法；将随机有限元方法引入可靠性计算中，建立了弹丸发射时的非线性随机有限元计算模型，并给出了计算中的一些问题的处理方法；在随机有限元的载荷边界的计算中，提出了弹带压力的有限元计算方法和在有限元求解思想上的数值计算模型。

The governing equation is the mild-slope equation. Finite element method has advantage to treat complicated boundary. The second order radiation boundary condition is expanded to improve the wave model for large incident wave angles. The validity of the second order radiation condition is examined through varying arbitrary wave incident angles.

模式将以包含波浪绕射及反射之缓坡方程式建立数值模式，利用有限元素法易於处理不规则边界的优点，引用二阶近似辐射边界条件，扩展波场模式处理大角度波浪入射的能力，探讨在未碎波的情形下，二阶辐射边界条件对於任意角度波浪入射之适用情形。

The gap element method is proposed in the paper for two kinds of problems, which include contact problem and gap joint problem. Elasticity contact problem falls into the category of unknown boundary value problems. It follows that the contact area and contact conditions or states can never be determined without special mathematical analysis, which is a very difficult work. The boundary conditions of the contact surfaces are deduced.

文中给出了间隙元法在空间可动部件接触问题中的应用，推导了其几何边界条件和力学边界条件，利用虚功原理推导了含间隙元弹性接触问题的有限元方程式，给出了其数值解法的迭代步骤，并指出了利用间隙单元进行分析的特点。

Do not gum up the work by telling mother what we are going to do .

别告诉母亲我们要干的事，那会把事情搞糟的。

In recent years, application of the partial prestressed concrete beam s is developed.

近年来，随着部分预应力砼梁应用的推广，发现我国规范所采用的名义拉应力法的计算结果不稳定。