摘要
涡激振动(vortex-induced vibration,VIV)是导致深海细长柔性立管发生疲劳破坏的重要因素。采用实验观测手段研究了长细比为1 750的柔性立管多模态涡激振动特性。实验中,通过采用拖车拖拉立管模型在水池中匀速行进来模拟均匀流作用下的涡激振动响应。利用光纤光栅传感器测量立管模型在横流向(cross-flow,CF)和顺流向(in-line,IL)的应变,进而通过模态分解的方法,获得立管模型涡激振动的位移。在此基础上,研究了CF以及IL方向的响应频率、位移标准差的平均值和最大值等随流速的变化规律,并分析了立管模型上测点的运动轨迹及其影响因素。
Vortex-induced vibration（VIV） is one of the most important factors accounted for the fatigue damage of long-flexible risers in deep water.Laboratory tests were conducted to investigate the multi-mode dynamic responses of riser model subjected to steady current flow.The riser model is 28 m in length and 1.6 cm in diameter,leading to a large aspect ration of 1750.The riser model was installed on a towing carriage,which might move horizontally above a wave basin with desirable speeds.Thus a uniform current could be modeled in a straightforward manner.The strain of riser model in both Cross-flow and In-line directions was recorded by the Fiber Bragg Grating（FBG） sensors and the displacements were obtained by means of the modal decomposition method.The variations of frequency spectrum and standard deviation of displacement with towing speed were examined.The orbital motion of typical cross-section of the riser model and its dependence were also investigated.
出处
《海洋工程》
CSCD
北大核心
2011年第1期18-25,共8页
The Ocean Engineering
基金
国家863计划资助项目(2006AA09A103)
国家自然科学基金资助项目(50921001)
海岸和近海工程国家重点实验室开放基金资助项目(LP0904)
关键词
细长柔性立管
涡激振动
动力响应
模态分解
long-flexible riser
vortex-induced vibration（VIV）
dynamic response
modal analysis
