# Analysis of Wind-Induced Vibration Response of Transmission Wire Under Crosswind in Canyon Terrain
## 8 Conclusions  
In this study, the distribution characteristics of the wind field and the wind vibration response of the wire under the condition of pulse wind and step wind in the terrain of the double-mountain canyon were examined using numerical simulation software and the strong bidirectional coupling calculation method. The influence of wind field variation on the wind vibration response of the wire was analyzed based on three aspects: the cross-sectional wind field pressure, the wire displacement, and the stress variation. The main conclusions are as follows:  
1. When the wind field reached the wire location after passing through the mountain, the wind speed decreased to a certain extent, and the windward side of the wire always bore the greatest pressure during the whole process of wind speed change. When the wind speed flowing through the wire became uniform, the pressure on the upper part of the wire was the same as that on the lower part of the wire, and the wire depended on inertia and gravity to oscillate;
2. Under the steady-state constant wind speed, the distance between the conductor and the mountain had little effect on the position of the wire's final stable state. The mountain size had little effect on the position of the wire's final stable state in the z-direction and reduced the height in the y-direction. The mountain suppressed the peak vibration in the z-direction and increased the peak vibration in the y-direction;
3. Under different step wind speed conditions, the displacement change trend of the wire in the inlet wind direction was the same and had a similar oscillation period. Finally, the wire entered a stable state after the same oscillation number. Therefore, the wind vibration response law of the wire was mainly determined by its own material characteristics;
4. Under the pulse wind speed condition, if the wind speed dropped and the wire swing in the z-direction was inconsistent, the swing amplitude in the z-direction was inhibited. If the difference in the pulse width between the two conditions was an integer multiple of the inherent oscillation period of the wire, the z-direction oscillation characteristics of the wire were consistent after the end of the pulse disturbance. If the difference in the pulse width between the two conditions was half of the inherent oscillation period of the wire, the z-direction swing amplitude of the wire was greatly reduced. The amplitude of the pulse wind did not affect the wire's oscillation period, and the wire's oscillation amplitude increased with the increases in the pulse wind amplitude. According to the wind vibration characteristics of the transmission wires, the wire spacing of some transmission part can be reasonably determined to avoid wind deviation tripping due to the close wire spacing. \begin{table}
\begin{tabular}{c c c c} \hline
**Condition** & \begin{tabular}{c} **Maximum Pre-Line** \\ **Wind Speed (m/s)** \\ \end{tabular} & \
\begin{tabular}{c} **Amplitude in the** \\ **z-Direction (mm)** \\ \end{tabular} &
\begin{tabular}{c} **Amplitude in the** \\ **y-Direction (mm)** \\ \end{tabular} \\ \hline
8 & 10.2 & 63.74 & 5.56 \\
5 & 15.2 & 116.17 & 15.94 \\
9 & 16.2 & 137.28 & 23.77 \\ \hline \end{tabular}
\end{table} 
Table 5: Maximum amplitude of swing variation. There is an important problem to be further studied, which is the problem of breakage of transmission wires under the ice condition by the impact of a wind field. In rainy and snowy weather, the transmission wires will freeze due to low temperature and moisture. In this case, the wire is prone to be overloaded which leads to wire breakage. We will discuss this issue in a future study. Conceptualization, J.C. and C.Z. ; methodology, C.Z. ; software, C.Z. ; validation, J.C.; formal analysis, J.C.; investigation, J.C.; resources, J.C.; data curation, J.C.; writing--original draft preparation, J.C.; writing--review and editing, C.Z. ; visualization, J.C.; supervision, C.Z. ; project administration, C.Z. ; funding acquisition, C.Z.