计算单元

A new Weibull Stress arithmetic in which Gaussian point is as a calculation unit is proposed. It can get more accurate result than the arithmetic in which Element is as a calculation unit.

1本文提出了以高斯点为单位计算韦布尔应力的新算法，在相同的有限元网格划分情况下，该算法比目前国际上通用的以单元为单位计算韦布尔应力的算法计算精度更高。

Then the boundary element integral equation of interior and exterior form is deduced in detail, also the form with corner coefficient. The significance for numerical calculation and principle of the singular integral is analyzed, and a non-isoparametric transformation method is presented to calculate weak singular integral and Cauchy integral, the method presented provides us a very simple way to computer the two kinds of singular integral of Helmholtz boundary integral equation, and it is easy to program in computer. After the difficulty of the calculation for multi-frequency of Helmholtz boundary element is explained, a method named SECHIEF (Series Expansion Combined Helmholtz Integral Equation Formulation), which is focused on the computational efficiency, is presented.

对结构声辐射的边界积分方程的内部形式与外部形式进行了详细的推导，给出了角点系数的计算方法与边界积分方程的形式，在此基础上，分析了奇异积分产生的原理及其对数值计算的重要性，提出了一种计算奇异积分的非等参(来源：Ae8a8BC论文网www.abclunwen.com)单元的变换方法，该方法给Helmholtz 声学边界积分方程中的弱奇异积分与Cauchy 奇异积分的计算以及编程提供了极大便利。

This article detailedly expatiated upon the principles, contents and methods of cropland classification; it analyzed the necessity to combine the work of cropland classification with GIS technology, summarized the attributions of ARC/INFOand some other related softwares; it established the technologic route of cropland classification supported by GIS, by a case study in Liwu Town,Li County Hebei Province, this article expatiated the practicable mechanism of combining the function of ARC/INFO with the work of cropland classification, and put forward some new ideas and approaches of utilizing GIS: this paper put forward the idea of coding the polygons in the basic graphic database such as soil map and land use map according to their attributes, and put forward the detailed coding project; based on the code databases, it expatiated upon the detailed approaches to create single梖actor map and output the final classification map; it put forward the principles and the method of creating classification units in the environment of GIS, that is how to keep the lines of soil polygon, the border of districts and the important objects such as residential areas, banks of rivers and roads ,and how to overlap single梖actor soil map and land use map, and to delete some vector lines of the overlapped map appropriately; it detailed the methods of creating mathematic model of classification coefficients in the environment of computer, and used FOXPRO6.0 programs to realize the automation of calculating coefficients; it represented the method of plotting the final map by overlapping various coverages according to the code tables and lookup tables, the process of outputting the cropland classifying map was finished by program.

本文法对耕地等别划分的原则、内容及方法作了较详细的阐述，介绍了多系数综合修正法的耕地等别计算方法及其具体应用和AHP的确权方法；分析了耕地等别划分工作与地理信息系统技术相结合的必要性，简要介绍了地理信息系统软件ARC／INFO及其他相关软件的功能特点，制定了地理信息系统支持下耕地等别划分的技术路线，通过对河北省蠡县蠡吾镇的实证研究，重点阐述了ARC／INFO及相关数据库软件与耕地等别划分结合的有效机制及GIS应用的一些新思想、新方法：提山了对土壤图和土地利用现状图等基础图形数据库进行特征编码的思想和具体的编码方案，阐述了基于与图形库相链接的特征编码表，单因素图提取、成果图的输出的具体实现方法；提出了GIS环境下耕地单元划分的原则和方法，即在保留土壤因素图斑界线、行政界线和重要地物等的原则下，将土壤单因素图和土地利用现状图进行拓扑叠加，对叠加图中的矢量线进行适当的删除；阐述了在计算机环境下，耕地分等参数计算模型建立的方法，并用FOXPRO6.0语言程序实现了参数计算的自动化；阐述了根据图形库特征编码表和建立绘图符号查找表，按不同图层叠加绘制成果图的方法，该过程用命令程序实现耕地等别图的输出。

With the modified method, the focal field of WSRT telescope was computed. Based on the result, the dense focal plane array was designed for the telescope. The weights of focal plane array were given by the conjugate field method and the far fields of WSRT were computed.

采用改进的算法计算了WSRT望远镜的焦面场，并根据计算结果设计了WSRT望远镜的致密焦面阵结构；用共轭匹配法对阵列单元加权、计算相应的远场方向图，并与采用单个馈源时的远场方向图作比较。

Secondly, the gun barrel temperature field is solved by two-dimensional and one-dimensional heat conduction model with finite element method and finite difference scheme respectively.

其次通过对身管二维轴对称传热模型和一维径向传热模型的数值计算，研究了身管固壁的传热问题。二维轴对称传热计算采用了有限单元法，一维径向传热计算采用了有限差分法。

Chapter 4 puts up the basic theory of non-linear finite element calculation methods and deduces calculation iterative formula and relevant accelerating iterative format. In the calculation of non-linear finite element, yielding element calculation is a difficult problem,"fictitious elastic stress" methods propounded in this paper puts the axe in the helve.

第四章提出了非线性随机有限元法的基本理论，并推导了计算迭代公式，为加快计算速度，提出了相应的加速迭代格式，对于基于非线性随机有限元的可靠度计算中，屈服单元的计算方法是一个难题，本文提出了"虚拟弹性应力"法，较好的解决这个难点。

In chapter six, A finite element model to evaluate the mechanics properties of thin wall structure is put forwards. The 4-node quadrilateral Hughes-Liu shell element with five through-the-thickness integration points is employed. The material is assumed to satisfy the elastic-plastic yield condition with isotropic hardening. The single surface contact algorithm is taken to deal with the contact searching. The priori stabilization procedures for the numerical control of the hourglass instability and the penalty method for the evaluation of contact force are used. The classical Coulomb law of friction is employed to evaluate the friction force.

第六章采用法向方向5点积分的4节点Hughes-Liu壳单元，前置参数法砂漏控制技术，等向强化弹塑性材料模型，分步增量应力回映方法，一体化接触搜寻算法，罚参数接触力计算方法及经典摩擦定律，建立了一种计算受冲薄壁结构大变形力学特性计算的有限元模型，通过对汽车A传动轴及汽车纵向方形吸能梁的大变形力学特性分析，验证了该有限元模型的正确性。

In this dissertation, many works have been done on the basis of the summarization of the merits of all kinds of meshless methods after a large number of relevant references are read and studied. The basic ideas, principles of meshless methods and their development in the recent years are introduced synoptically. Applications of Element-free Galerkin method in elastic foundation plate are studied deeply and some useful conclusions are obtained as follows:(1) Comparisons between numerical solutions and analytical solutions for several different styles of weight functions, including Gaussian weight function, spline weight function and singular weight function etc, are performed. The results show that Gaussian weight function is the best one.(2) Ranges of relevant parameters for Gaussian weight function are given.(3) Influences of nodal distribution schemes and the number of Gaussian integrated dots on computational results are discussed.

在本文中，作者在认真阅读和研究所搜集到的大量参考文献、综合各种无网格法优点的基础上，首先，对无网格法的基本思想、基本原理、发展现状作了概括性的介绍；其次，对无单元Galerkin法在弹性地基板计算中的应用进行了较为深入的探讨：(1)分别对高斯型、样条型、奇异型等不同形式的权函数进行比较分析，数值计算结果与级数解析解的比较表明，高斯型权函数效果较好：(2)对高斯型权函数进行参数研究，得到地基板计算中相关参数的选取范围；(3)对不同节点分布方案和不同高斯积分对计算结果的影响等作了有益的讨论。

Using three dimensional inharmonic element and the modified subspace iteration scheme for calculating dynamic characteristic of the shear wall, and using plane stress element and Newmark and Newton-Raphson method for calculation of seismic behaviors of shear wall under earthquake loads.

采用三维非协调实体元及改进子空间迭代方法计算剪力墙的特征对；采用平面应力单元并利用Newmark法与Newton-Raphson法相结合的方法计算剪力墙在地震荷载下的地震反应，并用FORTRAN77（F90）语言编制了相应的计算程序和前后处理程序，经计算验证程序是有效的。

The adaptability of arch dam to geology is more and more high, when the influence of complicated geology is considered, and the widespread used modern calculating methods in engineering, such as the finite element method, is considered during optimization design, the new challenge to old optimization design system of crown cantilever analysis is the full-automatic calculation problem of the different condition, different arch dam parameter, the possibility and the efficiency which were caused by the increments of calculation time.

高拱坝设计对地质条件的适应性要求越来越高，优化设计时要考虑到复杂地质条件的影响，最好采用已被工程界普遍接受的有限单元法等现代计算方法，这对以拱梁分载法为主的拱坝优化设计体系提出了新的挑战，除了需要解决不同条件、不同拱坝参数的全自动计算问题，还要解决由于结构计算时间增加所带来的优化计算的可行性和效率问题。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。