【作者】 尹鹏；

【导师】 方秦汉； 李黎；

【作者基本信息】 华中科技大学 ， 结构工程， 2009， 博士

【摘要】 发展特高压输电技术是国家“十一五”期间的重大技术政策，是电力与土木领域赶超世界先进水平的攀登计划，特高压输电线路的建设对我国经济的持续发展将产生重大作用。输电塔-线体系作为特高压输电线路的支撑体，它是由导线、绝缘子和输电塔组成的具有强烈非线性的复杂耦联体系，而大跨越则是特高压输电线路中跨越大江大河的塔-线体系。由于大跨越输电塔是一种高耸柔性结构，对风荷载等动荷载比较敏感，易产生较大的动力响应。对大跨越输电塔-线体系进行振动控制研究是电力工程与土木工程界一个重要的研究课题，既有其重要的理论意义，又有其重要的经济价值。本文的研究主要在大跨越输电塔-线体系的动力特性，风荷载特性和数值模拟，橡胶铅芯阻尼器的研发和布置方法，风振控制，风控效果的敏感性和验证，地震响应等方面开展，希望能给出在工程实际运用时大跨越输电塔的动力特性计算和风振控制方法的合理选择指引。主要工作包括以下方面：(1)研究了大跨越输电塔-线体系进行精细建模的方案，着重分析了对杆件和节点的不同处理对计算分析结果的影响。提出了基于模态识别技术提取大跨越输电塔-线体系中塔架第一周期的方法，归纳了考虑导(地)线及绝缘子的刚度和质量的影响后，大跨越干字型塔和酒杯塔的第一周期近似公式。研究了两种模型(简化导线体系模型与分裂导线模型)中塔架的自振周期和振型之间的差异，证明了可以用简化导线体系模型来代替分裂导线体系模型，进行各种动力响应分析。(2)编制了空间相关的风速场模拟程序WVFS，生成了设计风速下风荷载的时程样本。在精确模拟的基础上，对风场模拟结果进行了误差分析，推导了一个风场样本的均值、相关函数、功率谱函数、根方差等概率统计量的时域估计表达式。将由该风场产生的动位移与按电力设计规程简化计算方法产生的静位移进行了比较，证明了空间相关风速场的数值模拟是合理的。(3)研发了橡胶铅芯阻尼器，介绍了其工作原理和细部构造。通过对橡胶铅芯阻尼器进行性能试验，得到了加载频率、应变幅值和铅芯直径等因素对橡胶铅芯阻尼器性能的影响，对阻尼器的耐久性能进行了说明，推导了阻尼器各个参数的计算公式。研究了阻尼器的位置优化方法，并提出了具体安装方案。设计了实际工程中阻尼器的连接和安装方法，并讨论了阻尼器对主体结构的影响。(4)进行了橡胶铅芯阻尼器控制前后不同风向角的动风下大跨越输电塔-线体系的动力响应计算，分析了各控制点位移和各控制钢管内力的控制效果。研究表明：阻尼器控制后大跨越输电塔-线体系的位移、内力响应均大幅降低；各风向角动风作用下均会引起大跨越输电塔-线体系的横线向和顺线向振动；同时，位移响应的最不利风向角与内力响应的最不利风向角不一定相同；此外，顺风向风荷载调整系数得到有效减少，动力可靠度有所提高。(5)研究了大跨越输电塔-线体系风控效果的敏感性和橡胶铅芯阻尼器的实用性，从橡胶铅芯阻尼器的变形、刚度和阻尼各自的减振效果等方面验证了阻尼器的风控效果。研究表明：塔高和输电线张力均会影响大跨越输电塔-线体系的横线向与顺线向的位移和加速度响应和风控效果。在设计风速下，安装于优化位置的橡胶铅芯阻尼器均能正常工作，其刚度和阻尼对大跨越输电塔-线体系的风控效果均有贡献，阻尼发挥了主导作用。(6)用时程分析方法计算了地震作用下大跨越输电塔-线体系在橡胶铅芯阻尼器控制前后的时程响应。研究表明：地震作用下大跨越输电塔-线体系的位移响应远远小于设计风速下的动风位移响应，在设计工作中应以动风荷载作为输电塔的控制荷载。由于输电塔在地震作用下的位移响应很小，其控制效果相应较小。更多还原

【Abstract】 The development of special high-voltage transmission technology is one of the most significant technology policys of the Eleventh-five National Key engineering project, while it is the climbing plan to surpass the world’s advanced level in power and civil areas, whose construction will have significant function to our country’s sustained economic development. As the support body of special high-voltage transmission line, the tower-line system is a strong non-linear coupled system, which is composed by wire, insulators and power transmission towers, while the long-span is a special case across great rivers. Long-span transmission tower is a high flexible structure, it is sensible to dynamic load, especially to wind, which would easily generate significant dynamic response. It is an important researching subject for both power engineering and civil engineering to control the vibration of long-span transmission tower due to its important theoretical meaning as well as economical value.In order to provide a guide of the reasonable methods in natural vibration period and wind-induced vibration control, the dynamic characteristics, the numerical simulation of wind load, the research and development of lead-rubber damper, the effect of wind-induced vibration control and its verification, the seismic response deserve special attention. Consequently, study on the following aspects would be included in this dissertation.(1)Delicate modeling programs have been studied for long-span transmission tower-line system using finite element method, focusing on different treatments of the poles and nodes. Based on modal identification techniques, the natural vibration period of transmission tower in tower-line system were obtained for two different types, while the stiffness and weight of transmission line and insulator were considered. The natural vibration period and mode shapes of the towers in simplified model and bundle conductors model were researched, the former can be used to simplify the latter to execute a variety of dynamic response analysis.(2)A simulation program WVFS has been compiled to simulate applicable fluctuating wind velocity field in this paper. The examination was carried on from the detailed derivation of average value, correlation function, power spectral density and root variance. According to the research on simplified method of the electric power industry, it could be got that there are little differences between the displacements derived here by FELM time history method and that derived by simplified method, which means that the simulation on space relevant wind velocity field are reasonable.(3)The lead-rubber damper (LRD) was developed, while its working principle and structure were introduced. According to the performance testing, the loading frequency, strain amplitude, lead diameter and durability were considered, the formula for parameters of LRD were derived. According to the research on optimalizing location of LRD, the specific installation scheme was obtained. The connection and installation methods, the impact on the structure were discussed.(4)The time history analysis method was used to calculate the response of the wind-induced response of long-span transmission tower-line system. According to the research on the displacement and internal force of the main material under five wind directions, the effects of wind-induced vibration controlling were obtained. The most disadvantageous wind direction of the displacement and inner force are not always identical, so the different input wind direction in engineering design should be considered. Dynamic wind in different directions would lead to both transverse and longitudinal vibration of the tower. Besides, the adjustment factors along wind were obvious decreased, while the dynamic reliability has improvement in a certain extent.(5)The sensitivity of the controlling effect and the practicality of LRD were researched for long-span transmission tower-line system. According to the research on the deformation, stiffness and damping effect of LRD, the controlling effect is verified. The response and controlling effect of displacement and acceleration in transverse and longitudinal would be affected by tower height and tension of transmission lines. It is also proved that all the LRD are ensured to work under design wind velocity according to the research on LRD deformation; it is also proved that the controlling effect is not ideal when only member stiff is increased according to the research on controlling effect under dynamic wind when apply only stiff to the members on which the dampers used to be applied.(6)The time history analysis method was used to calculate the response of the seismic response of long-span transmission tower-line system. It is shown that the seismic displacement response is far less than dynamic wind, which means it should be based on dynamic wind loads in the design work. Due to the seismic displacement response is very small, the controlling effect is not ideal.更多还原