Liu Jinghua, Li Ziming, Liu Wenwu, Hu Changsheng, Zhang Chunhua
Equipment Department of State Grid Corporation of China, Beijing, 100031, China.
State Grid Heilongjiang Electric Power Co., Ltd., Harbin, 150090, Heilongjiang, China.
Sci Rep. 2022 Jul 5;12(1):11373. doi: 10.1038/s41598-022-15659-9.
The wind-induced fatigue is the main factor leading to reduction of the bearing capacity of long-span transmission towers. In order to reduce the harm of wind vibration, this paper takes the 500 kV Jiamusi region ISLSTT (in service long span transmission tower) as the research object, and a new kind of vibration reduction system is proposed based on a steel wire rope damping structure, with which the vibration characteristics of ISLSTT is analyzed. Firstly, the layout and components of the new vibration reduction system are described, and the damping performance of which is verified and analyzed by finite element method. Secondly, the nonlinear finite element dynamic simulation model of ISLSTT with the new vibration reduction system is established, and the multi-dimensional fluctuating wind speed time history satisfying Davenport wind speed spectrum is given by harmonic superposition method in the time domain. Based on the Bernoulli theorem, the corresponding time history of wind pressure is obtained, and the random wind load is applied to the finite element model to verify the feasibility and efficient of the new vibration reduction system. Finally, the aero-elastic wind tunnel test model of ISLSTT with the new vibration reduction system is built, and the time history curves of stress and acceleration at key points under different wind directions are obtained. By comparing with the un-damped system, it is demonstrated that the average damping efficiency of this method in the scale of stress and acceleration is 72.88% and 77.17%, respectively. The simulation and wind tunnel test results also demonstrate that the vibration reduction system based on wire rope damping structure can effectively reduce the vibration of ISLSTT caused by the non-uniformity of wind speed. The research results lay a solid foundation for the vibration reduction design of in service long span tower-line system in future.
风致疲劳是导致大跨输电塔承载能力降低的主要因素。为减少风振危害，本文以500kV佳木斯地区在役大跨输电塔（ISLSTT）为研究对象，提出了一种基于钢丝绳阻尼结构的新型减振系统，并对ISLSTT的振动特性进行了分析。首先，介绍了新型减振系统的布置和组成，并通过有限元方法对其阻尼性能进行了验证和分析。其次，建立了带有新型减振系统的ISLSTT非线性有限元动力仿真模型，采用谐波叠加法在时域中给出了满足 Davenport 风速谱的多维脉动风速时程。基于伯努利定理，得到了相应的风压时程，并将随机风荷载施加到有限元模型上，验证了新型减振系统的可行性和有效性。最后，搭建了带有新型减振系统的ISLSTT气弹风洞试验模型，得到了不同风向作用下关键点的应力和加速度时程曲线。与无阻尼系统对比表明，该方法在应力和加速度尺度上的平均减振效率分别为72.88%和77.17%。仿真和风洞试验结果还表明，基于钢丝绳阻尼结构的减振系统能够有效降低风速不均匀性引起的ISLSTT振动。研究成果为今后在役大跨塔线系统的减振设计奠定了坚实基础。
