Like racing cars that swerve and hit each other on a circular track, the moons' speed relative to each other is low because they travel in nearly the same orbit.

这有点像是突然转向的赛车在环形赛道上相撞，月亮们也在同一轨道公转，所以他们之间的相对速度很小。

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Vortex-induced vibration is limited amplitude response, but it occurs at low wind speed with relative large amplitude, which will affect the strength and fatigue resistance of the structure.

尽管涡振是一种限幅振动，但由于其发生风速较低，振幅相对较大，会影响结构的强度和疲劳，因此大跨度拱桥的涡振响应研究具有重要的意义。

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The vortex shedding vibration will take place at the relative low wind speed because of arches blunt section.

并且，钝体截面的主拱在低风速下容易产生涡激振动。

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