沿海某干字型钢结构杆塔的地震反应研究

沿海某干字型钢结构杆塔的地震反应研究(任务书,开题报告,论文16000字)
摘 要
 电能作为当今社会最高效的能源，早已成为人类赖以生存的资源，极大地加速了社会的发展。然而，由于地域差异及其他因素，一个地区电能的供求关系往往难以自行维系，这时就需要借助输电塔进行电力运输。输电塔多为高耸钢结构，作为重要的生命线工程，保证其稳定性至关重要。影响输电塔稳定性的外界因素中，风荷载是罪魁祸首。但是随着输电塔输电电压的逐年增大，输电线路经过区域的地震烈度越来越高，输电塔的抗震性能在设计中已不容忽视。
本文主要是以珠江口某典型钢结构输电杆塔为工程背景，结合工程实际，借助有限元软件SAP2000对其地震反应进行研究。结合实际工程中输电塔结构的基本信息，在SAP2000中对其进行有限元建模，通过模态分析对输电塔结构体系的动力特性进行研究，计算得出了体系的前9阶振型及其频率。然后选取El-Centro波、Hachinohe波、Kobe波、Northridge波及天津波五种地震波，调幅后分别从两个方向输入模型，提取典型节点的位移、速度、加速度以及典型杆件的轴力时程曲线来分析结构体系的动力响应。通过对比分析，研究影响结构地震反应的因素，并对输电塔的抗震设计提出相应的参考意见。
关键词：输电塔、SAP2000、动力特性、动力响应、时程分析

Abstract
As the most efficient energy nowadays, electric power has been the survival resources for human beings accelerating the development of society greatly. However, due to regional differences and other factors, the supply-demand relationship of electric power is hard to maintain for a district. Under this circumstances, transmission towers are always used to transport electric power. As an important lifeline project, transmission powers are mostly high-rise steel structure and so it is essential to ensure their stability. During these external factors which affect the stability of transmission towers, wind load is the main culprit. Nevertheless, with the transmission voltage increased year by year and the seismic intensity of area transmission towers pass through higher and higher, the seismic behavior of transmission towers cannot be ignored in the design.
This paper, combining with a large steel structure of the transmission tower engineering practice of Pearl River Estuary, by means of SAP2000, a finite element software, aims to research the seismic response of this transmission tower. Combined with the basic information of practical engineering structure, the finite element model of the transmission tower is built in SAP2000. Modal analysis is conducted to study the vibration characteristics of the structure, and the first 9 frequencies and mode of vibration are obtained. Then, El-Centro wave, Hachinohe wave, Kobe wave, Northridge wave and Tianjin wave are selected to input to the model from two directions after the amplitude modulation. The time-history curves of nodal displacement, velocity acceleration and elemental axial force are obtained to study the dynamic responses of structure. Through comparative analysis, the factors influencing the seismic response of the structure are obtained and several suggestions on seismic design of the transmission tower are put forward.
Keywords: transmission tower, SAP2000, dynamic characteristic, seismic response, time history analysis.

目录
第一章 绪论    3
1.1 引言    3
1.2 输电塔的基本信息    3
1.3 本文的主要内容    2
第二章 输电塔地震响应分析方法    3
2.1 引言    3
2.2 反应谱法    3
2.2.1 基本假定    3
2.2.2 基本原理    3
2.3 时程分析法    5
2.3.1 线性加速度法    5
2.3.2 Wilson- 法    6
第三章 输电塔的动力特性    8
3.1 引言    8
3.2 输电塔有限元模型    8
3.2.1输电塔有限元理论    8
3.2.2输电塔有限元模型建立    11
3.3输电杆塔动力特性分析    12
3.3.1 动力特性分析原理    12
3.3.2 ZGU302输电塔型输电塔动力特性分析    12
第四章 输电塔地震响应分析    15
4.1 引言    15
4.2 地震波的选取与处理    15
4.3 时程曲线输入方法    17
4.4 El-Centro波作用下结构动力响应    17
4.4.1加速度峰值100cm/s2时结构动力响应    19
4.4.2加速度峰值200cm/s2时结构动力响应    24
4.4.3加速度峰值300cm/s2时结构动力响应    29
4.4.4加速度峰值400cm/s2时结构动力响应    34
4.4.4 动力时程峰值对比    39
4.5 Hachinohe波作用下结构动力响应    43
4.6 Kobe波作用下结构动力响应    48
4.7 Northridge波作用下结构动力响应    53
4.8 天津波作用下结构动力响应    58
4.9五种地震波结构动力响应对比    63
第五章 结论与展望    65
5.1结论    65
5.2展望    65
参考文献    67
致谢    68