有限元法

A C++ program is developed for composing the stiffness matrix of the temperature field, saving it in changing bandwidth method and calculating the linear algebraic function group through using the Gauss eliminating method. A module for drawing the color fringe of tire temperature field is created, which makes the result more visual. Taking the 9.00-20 cross-ply tire on CA1092 as an example, the finite element numerical simulation analysis of automobile tire 2-D steady temperature field is completed. Through comparing the result with the analysis data by ANSYS, this software is proved to be capable of the modeling, calculating and post-processing of FEA of automobile tire 2-D steady temperature field.

采用C++语言完成了温度刚度矩阵的总体合成及其一维变带宽存贮，以及线性代数方程组高斯消去法求解等工作，采用C++语言实现了汽车轮胎二维稳态温度场云纹图的绘制，使得计算结果更加直观，也更能形象地显示汽车轮胎二维稳态温度场的分布状况，以CA1092（原CA142）五吨载货汽车用9.00-20尼龙斜交胎为例，进行了汽车轮胎二维稳态温度场有限元数值仿真分析，通过与ANSYS分析结果进行比较，说明所开发的有限元建模、求解以及后处理软件能够用于汽车轮胎二维稳态温度场有限元分析。

By the principle of penalt function, the irrotational fluid field is constrained, and author has proposed the Difference Method for distinguishing fluid vortex modes among the natural modes of coupled systems. Author has calculated the real frequencies with the extra deductive method, and discussed the influence of the numerical solution due to the irrotational constraint.

对于流体有限扰动时的非线性耦合系统的有限元分析作了一些探讨，给出了非线性系统的基本方程、变分原理及有限元方程，并具体地导出了三维几何非线性流体单元的切线刚度公式，采用增量形式的Newmark预报——校正逐步积分法计算系统的动力响应，由Newton-Raphson迭代法及其修正方法求解系统的非线性方程组，还列出了不平衡力余量检查和位移迭代增量检查等迭代收敛判断准则。

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。

Some new method is presented in this paper: A. An Integrated parameters computation method to analysis asynchronous operation of the turbine generator is given, including the equivalence of short circuit and open circuit of field windings, deducing boundary condition of 〓 method and computing frequency parameters. B. A new memory structure for sparse complex matrix and a PCCG method based on it are introduced to save memory and computation time. C. An equivalent method of vacuum is presented, and effectively eliminate the effect of corner point and accelerate convergence of PCCG method. D. Coupling the computation of electromagnetic and temperature field is discussed and model for computing temperature field of the turbine generator rotor at asynchronous operation is built.

文中提出了以下新方法：(1)在失磁异步运行转子三维涡流场计算中提出了完整的参数计算方法，其中包括励磁绕组开、短路的等效，〓法边界条件的推导及频率参数的计算方法；(2)提出了铁心内空气域的等效方法，有效地解决了开槽引起的角点奇异问题，并提高了方程组的迭代收敛速度；(3)在〓法有限元模型中，创立了一种能节约内存、提高计算速度的压缩存储矩阵格式，并建立了基于该格式的方程组解法；(4)提出了涡流电磁场和温度场两种不同场计算的合理结合方法，建立了转子三维稳态和时变温度场的有限元计算模型。

Using this method, calculated and analyzed the power loss of compound secondary with different size.

通过有限元分析法和通用解析法计算结果的比较，说明了有限元分析的正确性。

Based on the theory of probability statistic, a non-fixed value probability finite element analysis method by using FEA software ANSYS and Monte Carlo method was studied, by which the probability characteristic of projectile strength failure function was analyzed.

本文以概率统计为理论基础，综合采用有限元分析法和蒙特卡罗法，拟对弹体强度失效概率特征的非确定性概率有限元分析方法进行探讨。

Randomized orthogonal table is used to produce the specimens for radical basis function neural network.Self-organizing feature map is used to classify the specimens.

选取模具参数和工艺参数等作为影响冲压成形结果的因素，用正交表和随机法产生径向基函数神经网络的学习样本；利用自组织神经网络对样本进行分类，用有限元网格法反算的毛坯的长度作为神经网络的输出；设计了神经网络流程，定义了神经网络输出与有限元分析数据的相对误差。

The spectral element method based on a weak elastic mechanical equation extends the equation in the form of spectral with the idea of the finite element method. So it combines the advantages of the finite element method with the ones of the pseudospectral method.

谱元法是基于弹性力学方程的弱形式，运用有限元的思想在单元上进行谱展开，理论上该方法具备有限元适应任意复杂介质模型的韧性和伪谱法的精度。

Based on ANSYS, this paper considers the sluice valve and the base as a whole to take the Nonlinear Finite Element Study of the static and dynamic, at the same time discusses the interaction among sluice valve, pile and construction. Then some conclusions are drawn by comparing and analyzing the dynamic stress conditions of the gate chamber using response-spectrum method and time history method.

本文基于大型通用有限元软件ANSYS，将该水闸闸室结构与地基作为一个整体进行非线性静动力有限元计算，有效的考虑了地基-结构的相互作用，并将振型分解反应谱分析法和时程分析法的计算结果进行对比并得出相应的结论。

During the calculation of the early age temperature field, the early age physical and mechanical performance of concrete varies with its age, therefore in the second chapter we discuss the early age physical and mechanical performance of concrete and its development regulation with time, we emphasize elastic module and the development about the early age strength of concrete varying with time, at the same time consider the effect of shrink and creep upon the early age of concrete, in succession discuss how to confirm the physical parameter of thermodynamics of concrete.

之后讨论了混凝土的热物理参数的确定。为了能够正确合理的应用有限元方法求解早期混凝土温度场问题，第三章论述了求解温度场的有限元方法。第三章首先对热传导的微分方程作了阐述。之后确定温度场的边界条件。本章采用变分原理推导有限单元法计算温度场的公式。因此在第二小节叙述了变分原理，然后阐明了不稳定温度场的计算的三种方法，确定第四章分析中将采用向后差分法求解0#箱梁早期的温度场。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。