Theoretical Analysis and Experimental Validation on Galloping of Iced Transmission Lines in a Moderating Airflow
| Autor: | Fujiang Cui, Xuliang Li, Shuo Yang, Bing Huo |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Physics
Article Subject Continuous modelling QC1-999 Mechanical Engineering Airflow 020101 civil engineering 02 engineering and technology Mechanics Simple harmonic motion Geotechnical Engineering and Engineering Geology Condensed Matter Physics Wind speed 0201 civil engineering Superposition principle 020303 mechanical engineering & transports Amplitude 0203 mechanical engineering Mechanics of Materials Galerkin method Physics::Atmospheric and Oceanic Physics Civil and Structural Engineering Wind tunnel |
| Zdroj: | Shock and Vibration, Vol 2021 (2021) |
| ISSN: | 1875-9203 1070-9622 |
| DOI: | 10.1155/2021/9969435 |
| Popis: | Galloping of an iced transmission line subjected to a moderating airflow has been analysed in this study, and a new form of galloping is discovered both theoretically and experimentally. The partial differential equations of the iced transmission line are established based on the Hamilton theory. The Galerkin method is then applied on the continuous model, and a discrete model is derived along with its first two in-plane and torsional modes. A trapezoidal wind field model is built through the superposition of simple harmonic waves. The vibrational amplitude is generally observed to be more violent when the wind velocity decreases, except in the 2nd in-plane mode. Furthermore, the influence of the declining wind velocity rates on galloping is analysed using different postdecline wind velocities and the duration of the decline in wind velocities. Subsequently, an experiment has been carried out on a continuous model of an iced conductor in the wind tunnel dedicated for galloping. The first two in-plane modal profiles are observed, along with their response to the moderating airflow. Different declining rates of the wind velocity are also verified in the wind tunnel, which show good agreement with the results simulated by the mathematical model. The sudden increase in the galloping amplitude poses a significant threat to the transmission system, which also improves the damage mechanism associated with the galloping of a slender, a long structure with a noncircular cross-section. |
| Databáze: | OpenAIRE |
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