漫湾弧形闸门三维有限元应力分析

本文对漫湾弧形闸门作了三维有限元应力计算，并给出了弧门控制点处的位移和应力。计算结果表明，象漫湾闸门这样的大型弧门结构，只按照闸门规范制订的平面体系来进行结构的计算是不够的，其计算结果已不再偏于安全。文中对空间有限元计算结果做了分析，并和平面体系的手算结果作了比较，并依此说明现行规范中的结构计算所存在的缺陷。     

平面电动机气隙电感计算模型

介绍了一类应用于平面电动机的、具有多相绕组配置的、有铁心式电枢(简称平面电枢)的结构特点,建立了此类平面电枢的磁动势基波函数。利用磁场基本定律和磁场能量计算方法,推导了气隙磁场能量表达式。根据电感的基本定义,在气隙磁场能量表达式中,引入电感(包括自感和互感)系数。基于微积分即级数理论,对电感系数表达式进行简化,获得形式简单的电感计算模型。针对对称运行模式,获得了主电感和谐波漏磁电感的计算公式。此工作不仅解决了平面电动机主电感计算问题,而且,将传统电机学理论中的一维分布绕组电感计算方法拓展到二维平面分布绕组的主电感计算场合。     

有无横向联结系对小湾中孔弧门的影响

对于小湾中孔工作弧门这一高水头的弧形闸门,其主要构件的刚度较大,结构的节点效应和空间效应很强,现行闸门设计规范的平面体系算法过于简单,计算成果的误差较大,已不能满足大型深孔闸门结构计算要求.本文采用三维有限元法对该闸门进行结构分析和应力计算,并在此基础上分析有、无横向联结系对该弧门整体的变形和应力的影响,结果证明该弧门采用无横向连接系的方案更加优越,对闸门设计有较大的参考价值.     

石泉水电厂泄洪闸门的安全评估

通过对泄洪闸门的安全检测,综合考虑设计、制造安装和运行管理等方面的因素,引入一种安全评估的数学模型和评估体系,分析计算闸门的安全性指标和耐久性指标,并按照评定指标进行安全级别划分,对泄洪闸门的运行状态进行安全评估.     

石泉水电厂泄洪闸门的安全评估

通过对泄洪闸门的安全检测 ,综合考虑设计、制造安装和运行管理等方面的因素 ,引入一种安全评估的数学模型和评估体系 ,分析计算闸门的安全性指标和耐久性指标 ,并按照评定指标进行安全级别划分 ,对泄洪闸门的运行状态进行安全评估     

弧形闸门参数振动的有限元分析

参数振动是导致弧形闸门失事的重要原因之一。为对弧形闸门参数振动问题做进一步的研究,本文以主横梁、纵梁、支臂等构件组成的空间框架为计算模型,从弹性体的扰动方程出发,结合摄动理论,用有限元法求解框架结构的动力失稳区。通过对框架的动力稳定分析来确定弧形闸门的动力不稳定区,计算中考虑弧形闸门的空间效应和阻尼对不稳定区的影响。最后,通过对某工程的计算分析,证明此方法的正确性。该方法既是对弧形闸门参数振动计算方法的改进,也为弧形闸门结构动力稳定的进一步深入研究奠定基础。     

蜀河水电站1号厂房表孔闸门测试及有限元分析

应用ANSYS软件对蜀河水电站1号厂房表孔闸门进行了三维有限元静应力和干模态计算,得出了该闸门在静水压力下的应力分布规律和低阶频率,结合现场测试和有限元计算结果进行了分析,并对板梁组合建模方法在闸门计算中的应用效果进行了探讨.通过分析计算达到了了解闸门应力分布规律及安全状态的目的.     

平面闸门的导向装置

介绍平面闸门导向装置的两种型式,即分开式和整体式,并作了简要分析和比较,认为整体式导向装置可以简化闸门结构和门槽的埋设件,可显著提高经济效益,因此整体式导向装置应该在平面闸门中大力推广使用。     

水下爆破荷载作用下弧形闸门的塑性变形和位移

为得到水工弧形闸门正常运行时在水下爆破荷载作用下的动力响应,预测可能出现的极端状况,以对闸门结构进行反恐安全评价,探寻有效的反恐防护措施,借助ABAQUS有限元软件,采用显式动力分析方法,选取某试验得到的冲击力时程作为水下爆破荷载,考虑水体-闸门之间流固耦合作用,对一个实际弧形闸门结构进行了弹塑性时程分析。计算结果表明,水下爆破根据其发生位置不同对闸门结构冲击作用特点亦不相同,闸门破坏方式存在明显差别。闸门结构反恐安全防护重点区域为垂直隔板、边梁与上主横梁相交的部位和支臂铰支座附近部位。     

中小型潜孔式平面钢闸门设计程序系统

本文详细地介绍了中小型潜孔式平面钢闸门设计程序系统（ＦＧＤＰＳ系统）的基本构成、主要功能、运行环境及编制依据．并以菲律宾安盖特（Ａｎｇａｔ）水电站５号机尾水闸门设计为例说明了该系统的可靠性及实用住．此外．本文还介绍了国外一些平面钢闸门设计的先进理论和方法．     

Symbolic approach to inverse problems in method of moments

Symbolic computational systems introduce some unique features in computational engineering. There have been several papers published on the solution of differential equations under given boundary conditions by symbolic systems. The finite element formalism has received prime attention in the course of development of symbolic computation in engineering. The main idea has been to develop a symbolic FEM package to reduce the burden of manual algebra, eliminate errors introduced by numerical quadrature, and improve the efficiency of element generation. This work discusses a symbolic solution to electromagnetic linear antenna problems. The solution is a method of moments that transforms Pocklington's integral equation to a matrix equation. The symbolic system is used to produce (1) analytical integration, (2) the parametric expression for the input impedance and (3) computational code for forward and reverse problem of the input impedance.     

Carter's factor calculation using domain transformations and the finite element method

The main purpose of this work is to present a methodology to calculate Carter's factor using the actual air‐gap geometry, that is, without simplifications of the slot geometry. The methodology is based on the finite element method, and its results are compared with some traditional procedures used for Carter's factor calculation and also with a domain transformation technique. It is shown that the finite element method and the domain transformation methodologies present similar results, which are different from the results obtained with traditional procedures. Copyright © 2011 John Wiley & Sons, Ltd.     

基于ANSYS的轴流式水轮机空心活动导叶结构优化分析

活动导叶是水轮机的主要部件,对水轮机安全稳定运行具有重要作用。本文为提高轴流式水轮机空心活动导叶的刚度,同时控制其材料用量,采用有限元方法,研究了不同导叶瓣体内部结构对其刚度的影响。结果表明:导叶瓣体钢板厚度、纵向筋板厚度和位置以及内伸轴头长度对导叶刚度影响显著;横向筋板和多个纵向筋板对导叶刚度影响不明显。通过对不同结构重量的对比分析,提出轴流式水轮机空心活动导叶的优化结构,为同类型水轮机活动导叶设计提供参考依据。     

Efficient hybrid scheme of finite element method of lines for modelling computational electromagnetic problems

A hybrid scheme called finite element method of lines is proposed and described for modelling and analysis of generalized computational electromagnetic problems with emphasis on a number of irregular waveguide examples. This new technique is developed by combining a finite element method with a method of lines so that it can handle not only irregular composite geometry but also maintain high accuracy enjoyed by semi‐analytical procedures. Analytical and numerical algorithmic building blocks of this new scheme are discussed in detail such as geometry discretization, element mapping, element trial functions, reformulation and computational issues of non‐linear ordinary differential equations. Our results show that this new technique is able to efficiently solve complex problems as compared with the conventional method of lines. Copyright © 2004 John Wiley & Sons, Ltd.     

水泵水轮机活动导叶静应力评定探讨

活动导叶的应力评价是结构设计中的难点,本文通过对几个抽水蓄能电站活动导叶的刚强度有限元分析,探讨了水泵水轮机活动导叶的静应力评定方法.     

基于缩减基有限元法的灭弧室快速优化

针对高压电气设备电场逆问题的快速求解,将缩减基技术和有限元法有效结合,提出了一种用于快速求解电气设备电场逆问题的新方法,即缩减基有限元方法(reduced basis finite element method,RBFEM),分析了RBFEM的基本原理,并以气体绝缘开关设备(gas insulated switchgear,GIS)灭弧室的触头优化为例,详细介绍了基于RBFEM的快速优化算法的实现过程,包括建立数学模型、目标函数和设计变量的选定、给出优化策略、样本参数采样策略的选择、子域的分解以及样本参数N值的取值等关键问题。并对优化后的灭弧室触头形状利用ANSYS求解计算,得到的计算结果与RBFEM求得的计算结果相比误差为1.3%,可知RBFEM算法是有效的。     

多重网格法在HVDC线路离子流场数值计算中的应用

简要介绍了一种求解偏微分方程边值问题的有效方法——多重网格法,它比有限差分法和有限元法具有更高的计算效率和收敛速度。通过对HVDC线路非线性离子流场的计算表明,由多重网格法计算得到的结果比采用有限元法更接近于实际测量值。     

Computing the electromagnetic field of the system of arbitrarily positioned conductors in horizontally stratified multilayer medium

This paper presents a novel computational methodology, based on the finite element technique, for the analysis of electromagnetic field due to system of arbitrarily positioned current‐carrying conductors in horizontally stratified multilayer medium, having arbitrary number of layers with different characteristics (including air). Each soil layer is horizontally unbounded, homogenous and isotropic, whereas conductors can penetrate different layers and extend into the air. The effect of the stratified multilayer medium is taken into account by using the originally developed fixed image method. Complete electromagnetic coupling between grounding system conductors (satisfying thin‐wire approximation) is taken into account, whereas attenuation and phase shift effects are approximated. The electric and magnetic field in stratified multilayer medium are computed from the scalar electric and vector magnetic potentials, using the said fixed image method and approximations to the attenuation and phase shift effects. Copyright © 2014 John Wiley & Sons, Ltd.     

An interface‐enriched generalized finite element analysis for electromagnetic problems with non‐conformal discretizations

An interface‐enriched generalized finite element method is presented for analyzing electromagnetic problems involving highly inhomogeneous materials. To avoid creating conformal meshes within a complex computational domain and preparing multiple meshes during optimization, enriched vector basis functions are introduced over the finite elements that intersect the material interfaces to capture the normal derivative discontinuity of the tangential field component. These enrichment functions are directly constructed from a linear combination of the vector basis functions of the sub‐elements. Several numerical examples are presented to verify the method with analytical solutions and demonstrate its h‐refinement convergence rate. The proposed interface‐enriched generalized finite element method is shown to achieve the same level of accuracy as the standard finite element method based on conformal meshes. Two examples, involving multiple microvascular channels and circular inclusions of different radii, are analyzed to illustrate the capability of the proposed approach in handling complicated inhomogeneous geometries. Copyright © 2015 John Wiley & Sons, Ltd.