螺栓滑移对输电塔线体系的风振响应影响研究

发布时间：2018-03-24 04:11

本文选题：螺栓滑移　切入点：输电塔线体系　出处：《中国科学技术大学》2017年硕士论文

【摘要】：输电线路是我国电网的大动脉,为国计民生提供坚强的后盾。输电塔线体系拥有大跨、高柔等特点,在强风、地震、冰冻雨雪等自然条件下,输电塔极易发生倒塔破坏。其中,与输电线之间的耦合作用,使得塔线体系的动态特性、风振响应更加复杂,相关的深入研究可以为输电线路的设计提供参考。本文以课题组承担的某实际工程项目中的ZM-11猫头型单回路输电塔为背景,针对其塔线体系的动态特性以及风振响应进行研究。论文的主要内容包括:(1)风场模拟介绍了脉动风速的基本特性以及线性滤波法中的自回归模型(AR)。基于此模型,给出了利用MATLAB软件模拟的具有空间相关性的给定Davenport谱的脉动风速时程曲线的步骤,并将风速时程通过FFT变换所获得的谱与目标功率谱进行对比,验证了此种模拟方法的合理性和有效性。在此基础上,通过风速与风荷载的转换关系式得到风荷载时程曲线,以此来计算输电塔线体系的风振响应。(2)输电塔线体系的有限元建模及动态特性分析课题组针对输电塔中典型的螺栓接头,包括单螺栓、双螺栓、三螺栓连接接头进行了轴向拉伸试验,得到相应的位移-载荷曲线。基于ANSYS建立了螺栓连接的三维有限元模型,得到的位移-载荷曲线与试验结果作对比,利用相关的模拟参数,模拟得到塔腿与塔腿螺栓连接的位移-载荷曲线。利用非线性弹簧单元将位移-载荷曲线引入整塔的有限元模型中,建立考虑螺栓滑移的有限元模型。比较滑移模型与两种不考虑螺栓连接影响的传统有限元模型的模拟结果,验证了滑移模型的数值计算更接近试验测量结果。以这三种模型为基础,建立相应的输电塔线耦合体系,其中包括单塔双线和双塔三线体系,对其进行模态分析研究其动态特性,并提出螺栓滑移对输电塔及其塔线体系的动态特性的影响规律。(3)输电塔线体系的风振响应有限元分析考察了垂直输电线方向不同风速作用下输电塔线体系的时域响应,得出风速、塔线耦合效应以及螺栓滑移对输电塔风振响应的位移、加速度均方根的影响。通过对比拟静力风载作用下的杆件内力,研究风载作用下螺栓滑移对输电塔线体系动态响应内力方面的影响。
[Abstract]:The transmission line is the main artery of our country's power grid, which provides strong backing for the national economy and people's livelihood. The transmission tower system has the characteristics of large span and high flexibility. Under natural conditions such as strong wind, earthquake, frozen rain and snow, the tower is liable to collapse. Coupling with transmission lines makes the dynamic characteristics and wind-induced vibration response of tower system more complicated. The related in-depth research can provide a reference for the design of transmission lines. This paper takes the ZM-11 cat head single loop transmission tower as the background of a practical project undertaken by the research group. The dynamic characteristics and wind-induced vibration response of the tower system are studied. The main contents of this paper include: 1) the basic characteristics of the fluctuating wind speed and the autoregressive model in the linear filtering method are introduced. The steps of simulating the pulsating wind speed time history curve of a given Davenport spectrum with spatial correlation by using MATLAB software are given, and the spectrum obtained by the FFT transformation of the wind speed time history is compared with the target power spectrum. The rationality and validity of the simulation method are verified. On this basis, the time-history curve of wind load is obtained by the transformation between wind speed and wind load. The finite element modeling and dynamic characteristic analysis of transmission tower line system are used to calculate the wind-induced vibration response of transmission tower line system. The research group aims at the typical bolt joints in transmission tower, including single bolt, double bolt, single bolt, double bolt, single bolt, double bolt, single bolt, double bolt, single bolt and double bolt. The axial tensile test of three-bolt joint was carried out, and the corresponding displacement-load curve was obtained. Based on ANSYS, the three-dimensional finite element model of bolt connection was established, and the displacement-load curve was compared with the test results. The displacement-load curve of the bolt connection between the leg of the tower and the leg of the tower is obtained by using the relevant simulation parameters. The displacement-load curve is introduced into the finite element model of the whole tower by using the nonlinear spring element. A finite element model considering bolt slip is established, and the simulation results between the slip model and two traditional finite element models without considering the effect of bolt connection are compared. It is verified that the numerical calculation of the slip model is closer to the experimental results. Based on these three models, the corresponding transmission tower line coupling system is established, including the single-tower two-line system and the two-tower three-wire system. Modal analysis is carried out to study its dynamic characteristics. The effect of bolt slip on the dynamic characteristics of transmission tower and its tower system is presented. The finite element analysis of wind vibration response of transmission tower system is carried out. The time-domain response of transmission tower system under different wind speeds in vertical transmission line direction is investigated. The effects of wind speed, tower line coupling effect and bolt slip on the displacement and acceleration root mean square of wind vibration response of transmission tower are obtained. The effect of bolt slip on the dynamic response of transmission tower system under wind load is studied.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM75

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