中文摘要：

海洋工程中柔性圆柱结构疲劳破坏的主要诱因是海流引起的涡激振动。垂直来流作用下柔性圆柱涡激振动研究已取得诸多成果,然而在实际工程中,圆柱轴向与海流并不完全垂直,存在一定倾斜角度。针对这种普遍现象,学术界提出了倾斜圆柱涡激振动的不相关原则,但其正确与否至今存在争议。本文设计了室内模型实验,开展了长径比350,雷诺数800~16 000,质量比1.9,倾斜角度为15°的柔性圆柱涡激振动实验,通过对比垂直圆柱与小倾角倾斜圆柱的实验结果发现,在模态转化区域外不相关原则适用于小倾角倾斜柔性圆柱涡激振动分析,同时观测到在模态转化区倾斜圆柱更容易激发高阶模态。

英文摘要：

Vortex-induced vibrations （ VIV ） could cause fatigue damage in flexible cylinder structures for ocean en-gineering. VIV has been extensively studied through the canonical problem of a circular cylinder free to oscillate within a flow perpendicular to the body axis. In practical applications,the cylinder structures are frequently inclined with respect to the direction of the oncoming flow. S o m e researchers proposed the independence principle （I P） to simplify this complicated problem,but it remains controversial up till n o w. In this study,laboratory tests were con-ducted on VIV of an inclined flexible cylinder with a small y aw angle （15.） ,an aspect ratio of 350 and a mass ra-tio of 1.9. The Reynolds number ranged from about 800 to 16 000. The experimental results from a vertical cylinder and an inclined cylinder were compared. It was found that the IP is appropriate for VIV analysis of an inclined flexi-ble cylinder with a small yaw angle outside the modal transformation region. In addition,a high mode is more easily excited by an inclined cylinder in the modal transformation region.