风雨致大跨越输电塔—线体系倒塌破坏机理研究

发布时间：2018-01-14 10:41

本文关键词：风雨致大跨越输电塔—线体系倒塌破坏机理研究　出处：《山东大学》2017年硕士论文　论文类型：学位论文

【摘要】：我国处于季风性气候区,常出现狂风和特大暴雨等强对流天气。高耸柔性的大跨越输电塔-线体系是典型的风敏感结构,在风雨荷载共同作用下大跨越输电塔-线体系的振动疲劳损伤和连续性倒塌破坏时有发生。目前,国内外学者大多只单独考虑风荷载对结构的作用,忽略了雨荷载的影响。为保证输电线路运行的安全性、可靠性和稳定性,对风雨致大跨越输电塔的倒塌破坏机理研究具有非常重要的现实意义。本文以某大跨越输电线路为工程背景,深入研究了风雨荷载的作用机理,模拟生成了风雨速度时程,研究了风雨致输电塔-线体系的倒塌破坏机理。主要研究内容及结论如下:(1)基于建立的二维稳态风场,分析了下落中雨滴的高度H、雨滴直径d、地面粗糙度长度z0等参数对速度比γ的影响规律,忽略基本风速对速度比的影响,编程实现了雨滴速度计算程序,拟合了雨速与风速的速度比计算公式,称为"公式法",可以方便计算得到雨滴速度。(2)基于建立的二维紊流风场,充分考虑雨滴下落过程中脉动风速和雨滴惯性力等相关影响因素,基于MATLAB编程实现了雨滴速度计算程序,并给出了雨滴速度程序的流程图,称为"程序法",为今后数值模拟风雨场提供一种切实可行的模拟思路。(3)通过公式法和程序法模拟的风雨荷载时程对大跨越输电塔进行非线性动力分析,模拟了大跨越输电塔在风荷载单独作用和风雨荷载共同作用下的动力响应。当雨强为国内极值709.2 mm/h时,风雨荷载共同作用下比风荷载作用下的塔顶位移最大值增加了 15.4%。对于大跨越输电塔这种结构,雨荷载的作用不容忽视。(4)采用合理的倒塌模拟方法及破坏准则,对不同风攻角下的大跨越输电塔-线体系进行了倒塌模拟,分别研究了风雨致大跨越输电塔-线体系的倒塌破坏全过程、节间位移角和倒塌破坏机理。
[Abstract]:In China, strong convective weather such as strong wind and torrential rain often occur in the monsoon climate. The towering flexible long-span transmission tower-line system is a typical wind-sensitive structure. Vibration fatigue damage and continuous collapse of long-span transmission tower / line system occur from time to time under the combined action of wind and rain. At present, most scholars at home and abroad only consider the effect of wind load on the structure. In order to ensure the safety, reliability and stability of transmission line, the effect of rain load is ignored. It is of great practical significance to study the collapse and failure mechanism of wind and rain induced long span transmission tower. In this paper, the mechanism of wind and rain load is deeply studied with a large span transmission line as the engineering background. The wind and rain velocity time history is generated and the collapse and failure mechanism of wind-induced transmission tower-line system is studied. The main contents and conclusions are as follows: 1) based on the established two-dimensional steady wind field. In this paper, the influence law of raindrop height H, raindrop diameter d and roughness length z0 on velocity ratio 纬 is analyzed. The effect of basic wind speed on velocity ratio is ignored, and the program of raindrop velocity calculation is programmed. The formula of velocity ratio between rain velocity and wind speed is fitted, which is called "formula method", which can be used to calculate the velocity of raindrop. Considering the influence factors such as the pulsating wind speed and the droplet inertia force in the falling process of raindrop, the program of raindrop velocity calculation based on MATLAB is realized, and the flow chart of the program is given. Called "procedure method", it provides a feasible simulation idea for numerical simulation of wind and rain field in the future. The nonlinear dynamic analysis of long span transmission tower is carried out by the wind and rain load time history simulated by formula method and procedure method. The dynamic response of long span transmission tower under wind load alone and wind and rain load is simulated. When the rain intensity is the domestic extreme value of 709.2 mm/h. Compared with the maximum displacement of tower under wind load, the maximum displacement of tower under wind and rain loads is increased by 15.4. for long-span transmission tower, this kind of structure. The effect of rain load can not be ignored. (4) using reasonable collapse simulation method and failure criterion, the collapse simulation of large-span transmission tower and line system with different wind attack angle is carried out. The whole process of collapse and failure, Internode displacement angle and collapse failure mechanism of large span transmission tower-line system induced by wind and rain are studied respectively.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM75

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