查询词典 integral element

In chapter 2,all kinds of numerical methods of computational fracturemechanics are summarized,the development histories and present situation ofboundary collocation method,boundary integral method,finite difference method,boundary element method and finite element method are expounded,and theapplication of finite element method in fracture mechanics are emphaticallydiscussed.

第二章 总结了计算断裂力学中各种数值方法，论述了边界配位法、边界积分法、有限差分法、边界元法及有限元法的发展历史和现状，并着重讨论了有限元法在断裂力学中的应用。

For the Riemann boundary value problems for the first order elliptic systems , we translates them to equivalent singular integral equations and proves the existence of the solution to the discussed problems under some assumptions by means of generalized analytic function theory , singular integral equation theory , contract principle or generaliezed contract principle ; For the Riemann-Hilbert boundary value problems for the first order elliptic systems , we proves the problems solvable under some assumptions by means of generalized analytic function theory , Cauchy integral formula , function theoretic approaches and fixed point theorem ; the boundary element method for the Riemann-Hilbert boundary value problems for the generalized analytic function , we obtains the boundary integral equations by means of the generalized Cauchy integral formula of the generalized analytic function , introducing Cauchy principal value integration , dispersing the boundary of the area , and we obtains the solution to the problems using the boundary conditions .

对于一阶椭圆型方程组的Riemann边值问题，是通过把它们转化为与原问题等价的奇异积分方程，利用广义解析函数理论、奇异积分方程理论、压缩原理或广义压缩原理，证明在某些假设条件下所讨论问题的解的存在性；对于一阶椭圆型方程组的Riemann-Hilbert边值问题，利用广义解析函数理论、Cauchy积分公式、函数论方法和不动点原理，证明在某些假设条件下所讨论问题的可解性；广义解析函数的Riemann-Hilbert边值问题的边界元方法是利用广义解析函数的广义Cauchy积分公式，引入Cauchy主值积分，通过对区域边界的离散化，得到边界积分方程，再利用边界条件得到问题的解。

Spectral element methods for partial differencial equation is introduced in this study from viewpoint of the collocation approximation of Chebyshev polynomial. Wave Equation and its space discretization are deduced. Two time integral methods, central difference method and implicit Newmark method, are introduced, and their stability and applicability are also discussed in some details. The significance of absorbing boundary conditions in spectral element methods for Aeroacoustics is explained, and Clayton-Engquist-Majda absorbing boundary conditions is emphasized and introduced, then the discrete scheme of this boundary conditions is deduced and applied to spectral element methods for wave equation.

本文从Chebyshev多项式逼近理论出发，详细介绍了谱元方法求解偏微分方程的过程；推导了流体中的声波动方程并在空间上对其进行了谱元离散；详细讨论了两种时间积分方法──中心差分法和Newmark方法，分析了它们的稳定性条件，并从理论上对比了两种方法的优缺点和适用范围；将吸收边界条件推广应用于谱元方法求解气动声学问题中，重点介绍了Clayton-Engquist-Majda吸收边界条件的原理和公式，推导了该吸收边界条件的变分形式，并将其引入波动方程的离散形式中。

Based on hexahedra vector finite element in ANSYS,a new orthogonal-reinforced hexahedra vector element is created by modifying vector basis functions.Due to orthogonality of sampling nodes and orthogonality of integral simultaneously,the new vector element can strengthen diagonal elements' predominance and quicken speed of solving system question group.

在ANSYS采用的六面体矢量单元的基础上，对矢量基函数作了一些增强正交性的修改，使其同时具备采样点正交性和积分正交性，得到了一种新的正交增强六面体矢量单元；这种新单元能增强系统矩阵的对角占优特性，加快系统方程组的求解速度。

Different kinds of integrations have to be evaluated in boundary element methods. The nearly singular integral is the most difficult one of them. A self-adaptive Gauss integral method is proposed to divide the element into finer meshes under the specified conditions.

边界元法通常需要采用数值方法解决单元内的各种积分问题，而准奇异积分是各种积分中数值处理最为困难的部分。

The mild-slope equation with current effects is reformulated to an inhomogeneous Helmholtz equation. Applying the conventional boundary element method to this inhomogeneous equation, the inhomogeneous part will result in a domain integral which makes the computation complicated and messy. To improve this drawback, the DRBEM is adopted to transform the domain integral to boundary integral.

首先将含水流效应之缓坡方程式重新整理为非齐次之Helmholtz方程式，再利用Green公式改写为积分方程式，但利用一般传统边界元素法解析时，将存在一领域积分项，使得边界元素法显得繁杂且不完美，为改善此一缺陷，本文乃应用双互换边界元素法之技巧，以节省大量之数值计算时间。

This paper puts forward the triangle element method for calculating gravity anomaly of three-dimensional sphere-coronal model by using the divergence theorem. In this study, the volume integration was changed into surface integral, a series of triangles were used to fit the surface, and then the Green's formula was adopted to change surface integral into line integral. At the same time, a reasonable calculation program was given.

提出利用高斯公式将体积分变成包围该积分域的全表面积，应用一系列三角形拟合计算表面，然后通过格林公式把对每个三角形的面积分变成对三角形每边的线积分之和的三角元法来计算三度体球冠模型重力异常，同时给出了合理的计算方案。

Firstly, the paper introduced the working principle and device of the two-pass grate-rotary kiln and had an analysis method of mechanics of the tyre. We have put forward the finite element analysis of the contact stress of the tyre-roller based on the whole construction mode of shell-kiln liner-large gear-tyre-roller of the rotary kiln and obtained the strength and distributing rule of the tyre's contact stress. The research shows that within one week the contact stress mainly lies in two leading peak value and catastrophe which appear at the contact zone of the tyre and supporting roller. Then we regarded the tyre's stress as the test of unknown plane stress of principal stress. Utilizing mature and modern testing technology, we raised the testing principle and scheme of tyre stress and then had a on-the-spot test of the stress. Comparing the analysis result of the test with the one calculated from the finite element analysis, it proofed the rationality of finite element analysis method of integral modeling and the correctness of the contact stress result of the tyre and roller. Finally, for two-pass of similar rotary kilns, using the ANSYS APDL re-development technology, carried on the re-development about the overall finite element analytic method of thecontact stress of tyre-roller.

首先，本文介绍了2档回转窑的工作原理和装置，对滚圈的力学行为进行了分析，提出了基于筒体-滚圈-托轮的回转窑整体建模的有限元分析法，来对滚圈-托轮的接触应力进行有限元分析与计算，得到了滚圈接触应力的大小和分布规律，并求得滚圈外中内圈节点的主应力；其次，把滚圈的受力看成是主应力未知的平面应力的测试，利用现代测试技术，提出了滚圈主应力测试的原理和方案，并对滚圈的主应力进行了现场测试，现场测试分析结果与有限元分析计算出的主应力相比较，证明了整体法建模的有限元分析方法的合理性和滚圈-托轮接触应力结果的正确性；最后，利用ANSYS的APDL的二次开发技术，针对2档同类回转窑，就滚圈-托轮接触应力的整体有限元分析法进行了二次开发。

For the first time the endplate bolted connection's finite element model with the original crack is set up by the singular element, the fracture problem study is introduced to the finite element analyzing. The J integral value and stress intensity factor of the crack tip are calculated by the ANSYS Parametric Design Language program, and the developing of original crack is judged from the K Rule and J Integral Rule.

第一次通过构造奇异单元来建立带初始裂纹的节点有限元模型，将断裂问题的研究引入到端板螺栓节点的有限元分析中，并通过ANSYS软件中Parametric Design Language编程来计算裂纹尖端的J积分值、应力强度因子，根据断裂力学中的K准则、J积分准则判断初始裂纹是否会重新启裂。

The results show the high accuracy quality of spectral element method and the stability of Newmark time integral method. Then some computational parameter is changed in example one such as the subdivision style of computational domain, time step length and such on. Some important conclusions and strategies for spectral element method with Newmark integral method for computational aeroacoustics can be given. The feasibility of spectral element method for computational aeroacoustics is verified.

计算结果表明谱元方法的高精度及Newmark时间积分方法的稳定性，并改变算例的计算参数，例如计算区域剖分方式、时间推进步长等进行了计算，得出了一些重要结论，为使用谱元方法结合Newmark积分求解气动声学问题积累了重要的经验，最终证明了谱元方法求解计算气动声学问题的可行性。

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Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。