有限元法

Advanced numerical simulations were introduced in soil water research,such as finite analysis method,characteristic finite element method,and alternating direction finite element method.

土壤水研究的数值模拟方法也有一些突破，如有限解析法、特征有限元法、交替方向有限元法等。

Objective: To get objective evidence of the optimal stress condition in broken ends of scaphoid loins fracture, to provide biomechanical basis for the clinical choice of the different fixation postures after scaphoid loins fracture and further to offer theoretical instructions for the treatment after scaphoid loins fracture, stress distribution and shift rules after three types of fracture in scaphoid loins (transverse fracture, radialis oblique fracture and ulnar side oblique fracture) were studied using electrometric method and three-dimensional (3-D) finite element analysis.

目的：运用电测法和三维有限元法，研究腕舟骨腰部三种类型骨折后腕关节在各种不同体位固定下骨折端的位移情况及其所受应力的分布和变化规律，从而得到骨折后良好折端应力条件的客观证据，为临床上腕舟骨腰部骨折后腕关节固定体位的选择提供生物力学依据，进而为腕舟骨腰部骨折后的临床固定治疗提供理论指导。方法：采用电测法和三维有限元实验方法进行生物力学测试。

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。

And presents some commonly process and attentions in applying the FEM software ANSYS to PCM analysis.2 Analyzed the PCM performances under the affection of piezoelectric and polymer"s material characteristic by FEM, and got the rule.3 Analyzed the PCM performances which affected by stickup layer"s materials characteristic and its thickness under the application of FEM.4 Based on the construction principles of 1-3 type orthotropic piezoelectric composite materials, the finite element model is designed and its orthotropy is analyzed, at the same time, the length/broad ratio to PCM orthotropy is also analyzed.

二、应用有限元法分析了压电相材料和聚合物基体相材料特性对于压电复合材料综合性能的影响规律。三、应用有限元法分析了粘贴层的材料性质和厚度尺寸对压电复合材料在实际应用中性能的影响规律。四、根据提出的正交异性压电复合材料的构造原理，设计出1-3型正交异性压电复合材料的有限元模型并分析其正交异性，同时分析了压电相材料长宽比对其正交异性的影响。

First,it mainly utilizes analytics to deduce formula of slot leakage reactance.It considers three instances,including monolayer-slot,multilayer isometric-slot and multilayer anisometric-slot.Then,the analytics and the FEM are utilized to calculate slot leakage reactance of stator winding of prototype of Powerformer and compare their results.Second,the theory of utilitzing FEM to calculate the reactance of Powerformer is simply introduced,including stable reactance,transient and subtransient reactance.Specially,the saturated influence of the stable reactance is considered.Then, the results are analysed.Final,it mainly introduces the influence of harmonic magnetomotive force of stator winding and analyses the harmonic magnetomotive force of stator winding.

首先是用解析法推导出Powerformer定子绕组槽漏抗的计算公式，考虑了单层圆形半闭口槽、多层等半径圆形半闭口槽和多层不等半径圆形半闭口槽三种情况，并对Powerformer样机的定子绕组槽漏抗用解析法和有限元法进行了计算，并比较其结果；其次，简要介绍了有限元法计算Powerformer电抗参数的原理，包括稳态电抗、瞬态电抗和超瞬态电抗，对稳态电抗考虑饱和影响，对结果进行分析；最后，介绍定子绕组谐波磁势对电机运行性能的影响并对定子绕组谐波磁势进行了分析。

In this thesis, the application of FEM in the special cars frames has been studiedIn the chapter 1 of this thesis, the basic principle of FEM is introduced, and the application of FEM in static and dynamic analysis of a car frame is discussed briefly, considering its structure and load properties.

本文结合工程实例，对特种车车架的有限元静力、动力分析作了一些探讨。本文第一章介绍了有限元法的基本思想，并结合汽车车架的具体结构和载荷特点，对利用有限元法进行静力、动力分析的有关问题进行了阐述。

In this dissertation, based on the systematically analysis of theory and application research on deformable model, a new B-spline active contour based on the finite element method is proposed; then B-spline active contour is applied to fitting the digital curve cross-sectional contour, and adaptive FEM is adopted to improve the precision; lastly the model is generalized to 3D, and a B-spline active surface model based on FEM is proposed.

本文在系统地分析了国内外关于可变形模型理论与应用研究的基础上，提出了一种基于有限元法的B样条主动轮廓模型；并将其应用于由断层图像导出的截面轮廓数字曲线的拟合，利用自适应有限元技术提高拟合精度；最后将其推广到三维，提出了基于有限元法的B样条主动曲面模型。

Based respectively on elastic ground beam and finite element method, two dynamic prediction methods for displacement of foundation pit are developed by the light of bionic algorithms. The case studies demonstrate that the two methods have advantage over other methods.

通过修正土压力分布模式，利用仿生算法，建立了基于弹性地基梁有限元法的深基坑支护结构位移与安全性动态预报模型和计算方法，两个算例表明，该法比规范推荐的弹性地基梁法的预测精度要高；同时，建立了基于连续介质有限元法的深基坑支护结构位移与安全性动态仿生优化预报法，算例计算结果证明了该法比同类方法计算结果要好。

Based on Galerkin finite element method, a new upwinding finite element numerical model suitable for modeling wind driven current in shallow lakes is derived by introducing streamline upwinding method and the selective lumping coefficient matrix scheme.

从控制方程组出发，以 Galerkin有限元法为基础，引入沿流线加权的权函数(沿流线加权的迎风有限元法)和选择性集中系数矩阵方法，推导、建立了一适合于浅水湖泊风生流计算的二维迎风有限元数值模型。

The analytic solution of plane distribution of water depth and velocity in curved open channels are also given, which is better than those only giving depth-averaged velocity in radial direction.

但有限元法作为一种域法，不适合用于无界域的计算，且有限元法及边界元法的收敛性、稳定性目前还不能从理论上加以证明，计算误差也无法精确预测。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。