【作者】 郭勇；

【导师】 孙炳楠；

【作者基本信息】 浙江大学 ， 结构工程， 2006， 博士

【摘要】 大跨越输电塔线体系作为高压电能输送的载体,是重要的生命线工程。与通常的架空线路相比,大跨越塔线体系具有塔体结构高、跨度大的特点,塔体的高柔特性决定了风荷载是其主要动力荷载,而塔线间的相互作用,使这类体系在风载作用下的振动响应十分复杂。 本文以规划中的世界第一高塔—舟山大跨越输电塔为工程背景,建立了塔线耦合体系的空间有限元模型,分别采用梁单元、杆单元、悬链线索单元对输电塔、绝缘子和输电线进行了精确的模拟。同时采用离散刚度法设计制作了塔线体系的气动弹性模型,并在紊流风场中,进行了多个风向角、多个风速下的单塔和塔线体系气弹模型风洞试验。 通过对塔线体系风振响应的时域分析和试验研究,将输电塔的响应分解为共振分量与背景分量,并分别考虑了塔线耦合作用对这两部分分量的影响。针对背景与共振响应各自的特征,进一步提出了塔线体系的简化计算方法:背景分量的计算可以应用准静态假定,采用方差分析法得出;通过建立塔线体系的等效计算模型—悬吊摆系统,使共振分量的计算获得简化。以简化方法为基础,采用频域方法对塔线体系的风振响应进行了计算。通过对计算结果的分析,得出了一些重要的结论,对塔线体系的实际工程设计具有重要的指导意义。 针对塔线体系的动力特性,采用被动耗能装置—粘弹性阻尼器对体系的风振响应进行了振动控制研究,重点讨论了阻尼器的位置优化问题。利用本文提出的改进适应性权重:代间比较权重,并将遗传算法与劣出优入算法相结合,形成了一种多目标优化的混合遗传算法。选取塔线体系脉动位移的H₂和H_∞范数、阻尼器的总量与阻尼器平均耗能作为优化目标函数,得到了阻尼器的优化布置方案,并通过受控体系的气弹模型风洞试验对风振控制效果进行了验证。计算和试验结果均表明,该方案可以取得较好的减振效果,从而为将来塔线体系风振控制系统的实际安装提供了理论依据。更多还原

【Abstract】 Long span transmission line system is the lifeline project as the electric powe’s carrier. Comparing with the normal overhead transmission line system, the long span transmission line system has higher transmission tower and longer span. Wind force is the dominant load due to its characteristics. The wind-induced dynamic response of this kind of structures is very complicated because of the interaction between the tower and the lines.A tallest transmission tower in the world, which is a part of the ZhouShan long span transmission line system is studied and a spatial finite element modal of the tower-line coupled system is established in this dissertation. The tower, isolator and the transmission line are simulated with the beam element, truss element and catenary cable element individually. A aeroelastic model is designed with discrete stiffness method and the wind tunnel test of the single tower model and tower-line system model have been conducted with different wind directions and velocities in the turbulent flow.Based on the time-domain analysis and experimental study, the response of the tower can be divided into two parts: background response and resonant response, and the influence of the transmission line is considered in the analysis. The simplified method to calculate the dynamic response is proposed according to the different features of the two parts: the background response can be calculated with the covariance analysis based on the quasi-static presumption;the resonant response can be calculated easier after predigested the transmission line system as a suspended mass pendulum system. The wind-induced dynamic response in frquency-domain is calculated with the simplified method and some important conclusions which will direct the design of long span transmission line system are obtained.The viscoelastic dampers taken as a passive energy absorbing devices are used to control the wind-induced dynamic response of the long span transmission line system for its dynamic characteristics and the emphasis of the discussion is focused on the dampers’ optimal placement methods. A hybrid genetic method which is composed of the genetic algorithm and worst-out-best-in search algorithm based on the multi-objects optimization and a ameliorative adaptive weight method: generation compared weight method are presented. The H₂ norm and H_∞ norm of the transmission tower’s displacements, the totalnumber of the dampers and the average energy absorption in a damper are selected as the objective functions. Applying the proposed optimal method, the feasible damper distribution within the tower can be obtained. The theoretical analysis and wind tunnel experimental results show the efficiency of the controlling system and provide the theory basis for the erection of the system in the future.更多还原