| Summary: | In this study, three-dimensional finite element models of high-mast light poles without and with spiral helical strakes were built using ANSYS software to investigate their vibration characteristics in a wind environment. Based on a two-way, fluid–structure interaction simulation method, the dynamic responses of the high-mast light poles under different windspeeds were analyzed. The results indicate that the high-mast light pole structure without spiral helical strakes may suffer from evident vortex-induced vibration, which is dominated by the third vibration mode in the windspeed range of 5~8 m/s, whereas the light pole with spiral helical strakes had no obvious vortex-induced vibration. The external helical strakes can amplify the along-wind response of the light pole to a certain extent, while significantly decreasing its crosswind vortex-induced response. The vibration suppression effect is better when the value of pitch <i>P</i> is small. Practically, if <i>P</i> = 7.5 <i>D</i> (<i>D</i> is the diameter of the dominant vibration mode), the vibration suppression effect is best. On the other hand, if the value of pitch <i>P</i> remains constant, the vibration suppression effect increases with the height <i>H</i> of the outer helical strakes. However, excessively high outer helical strakes may also increase the along-wind response of the structure. In general, when spiral helical strakes are used in design, the recommended values of <i>P</i> and <i>H</i> are <i>P</i> = 7.5 <i>D</i> and <i>H</i> = 0.20 <i>D</i>.
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