输电塔架的力学强度分析

机械设计制造及其自动化文档，文档编号:JX1318 文档字数:16784.页数:40 附任务书，开题报告，文献综述,外文翻译

 摘  要
 
 输电塔架结构是送电工程中的重要结构，其结构设计安全性意义重大。我国现行《电力设施抗震设计规范》GB 50260-96及《架空送电线路杆塔结构设计技术规定》DL/T 5154-2002仅对500kV以下杆塔结构做了下述规定：8度及8度以下时，自立式铁塔可不进行抗震验算。该规定尙缺乏充分的研究支持。另外，随着电压等级的提高，输电塔架结构的高度和重量也随之增加，地震作用对结构设计的影响加剧，是否需要进行抗震验算，要充分考察结构控制内力才能确定。目前为止，结构控制内力的分析已成为工程设计和规程编制修订亟待解决的课题之一。本文在总结已有研究资料和成果的基础上，对输电塔架结构设计理论进行了分析讨论，并以华北电力设计院提供的典型塔型――大跨越塔和酒杯塔为工程背景，以空间桁架有限元杆系模型为理论基础，考虑地震、风、不同风速和不同高度等工况，运用SAP2000有限元软件，建立了特高压输电分析模型，进行了各塔架结构的动力特性和地震反应分析，对比研究了非抗震和抗震两种组合情况下，塔体各部分杆件的设计控制内力，并总结风速和高度影响下，各部分杆件内力变化规律，进而确定输电塔架结构是否需要进行抗震验算，通过以上对比研究得到以下主要结论：
1)在进行地震响应分析的时候，现行规范的取前2~3个振型是不能满足工程精度要求。本文建议参考建筑结构规定的，取用质量参与系数达到90%以上的振型个
数。
2)随风速增大，塔身主材考虑地震作用效应组合与不考虑地震作用效应组合杆件内力比值逐渐减小。
3)横隔面的受力相对较小，一般情况下无论是否考虑地震效应组合其设计内力
均不起控制作用，主要根据长细比等条件控制结构选材，但在设计过程中必须考虑到横隔面对塔架变形的约束作用，适当加强横隔面部位杆件的构造措施。
关键词：超高压输电塔架 风荷载 地震作用 控制内力
ABSTRACT
 
Tower structure is very important in transmission line.Its security is very importantfor structure design.The current code which guide tower designing in transmission line,‘Code for design of seismic of electrical installations’ and‘TechnicalRegulation of design for tower and pole structures of overhead transmission line’ indicate that:it is not necessary that seismic checking calculation is done forself-supporting transmission tower if the seismic fortification intensity is 8 degree orunder 8 degree.There is not enough scientific basis about this define.Otherwise,alongwith the improvement of voltage grading,the height of transmission tower becomeshigher and higher,and the span of two towers becomes larger and larger.The earthquakefunction's influence to structure design turns worse,Whether carrying on anti-seismicchecking or not,controlling force play an important role.Now,one subject is the study ofcontrolling force in the course of structural design and code amendment.In this dissertation,on the basis of reviewing the study and design data available,thestructural theory of transmission tower is discussed,type tower-large span transmissiontower as engineering background and Space truss finite element method as theoreticalfoundation.Various load cases taken account such as:earthquake effect,wind load,etc,transmission tower model established by SAP2000 software,the dynamic characters andseismic response are analyzed.the controlling force of the elements on tower arecompared whether considering the earthquake effect or not.Then,compare the regularityof the elements’force with the change of wind speed and tower height.So we can getsome conclusion as following:
1)More modes should be considered according to the modal mass participation ratio when the seismic response of the structure was investinated.We suggest that numbers of the modes whether the modal mass participation ratio achieve 90%or not.
2)Force controlled by wind with wind speed variation and height below 185m,and
it don’t need seismic checking if the seismic fortification intensity is 8 degree or under 8degree.Because the span of two towers in tower-large span transmission tower is toolarge,constitution measures should be stiffened on the web materials of the cross arm.
3)Generally,whether considering seismic effect or not,the internal force of the diaphragms is not the main facts for its small value during materials selected,we usually select the materials according to slenderness ratio,but the constitution measures should be stiffened because of its confinement to tower.
Key words:High voltage transmission tower,Wind load,Seismic effect,control force

 目   录
摘要 I
ABSTRACT II
第一章、绪论 8
1.1研究目的和意义 8
1.2输电塔架结构体系国内外研究现状 9
1.3本文主要研究工作 11
1.4技术路线 11
第二章、输电塔架结构设计基本原理 12
2.1输电塔架的特点和种类 12
2.2空间桁架有限元法 14
2.2.1计算简图 15
2.2.2质量矩阵 15
2.2.3杆件坐标变换与刚度矩阵 16
2.2.4塔架正则方程及其解 18
2.3塔体荷载 19
2.3.1导线及地线风荷载标准值 19
2.3.2杆塔风荷载标准值 20
2.3.3地震作用 20
2.4荷载效应组合 22
2.4.2考虑地震作用效应组合 23
2.5本章小结 23
第三章 输电塔架不同有限元计算模型的结果对比 24
3.1工程背景 24
3.1.1软件介绍 24
3.1.2酒杯塔ZB3 24
3.2 SAP2000有限元软件建模 27
3.2.1基本假定 27
3.2.2有限元模型对节点的处理 27
3.2.3荷载处理及动力特性分析方法 28
3.3 SAP2000模型与TTAP模型杆件内力对比 28
3.3.1重力作用下杆件内力对比 29
3.3.2风作用下杆件内力对比 30
3.5本章小结 31
第四章 典型塔型的分析结果 32
4.1本章主要分析内容 32
4.2按不同风速设计模型对比 32
4.2.1结构动力特性对比 33
4.2.2内力对比分析 34
4.3本章小结 38
第五章 结论 40
致  谢 41

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