不同频率比时立管两向涡激振动及疲劳分析  

Vortex induced vibration and fatigue damage of risers under two-dimensional vortex excitation considering different frequency ratios

作　　者：唐世振[1] 黄维平[1] 刘建军[1] 邓跃[1] 

机构地区：[1]中国海洋大学海洋工程山东省重点实验室,山东青岛266100

出　　处：《振动与冲击》2011年第9期124-128,共5页Journal of Vibration and Shock

基　　金：国家自然科学基金重点项目资助(50639030)

摘　　要：考虑四种不同频率比(流向荷载频率/横向荷载频率)情况下,立管两向涡激振动的幅值和疲劳的变化。结果表明:较低频率比且低约化速度条件下,流向自由度对横向振动具有一定的抑制作用;当6.3<约化速度<8.0时,考虑顺流向振动时横向振动幅值明显增加。随着频率比的增加,顺流向振动对横向振动的影响逐渐减弱。横向振动对顺流向振动的影响在四种情况下均较为显著,考虑横向振动时顺流向振动幅值急剧增大。两向自由度涡激振动的疲劳在低频率比时明显高于单自由度时的疲劳;顺流向振动疲劳随着频率比的增大受横向振动的影响越来越明显。The response amplitude and fatigue damage of risers under two-dimensional vortex excitation were studied and their variations under four kinds of different frequency ratios（drag force frequency/lift force frequency） were focused.The results show that under low frequency ratio and low reduced velocity,the in-line vibration will restrain the cross-flow vibration.Under the condition of 6.3 reduced velocity 8.0,the cross-flow amplitude will increase obviously,if considering the effect of in-line vibration.With the increase of frequency ratio,the effect will be weakened.The cross-flow vibration influences the in-line vibration severely in all the four cases.The in-line amplitude will increase evidently,when considering the effect of cross-flow vibration.The fatigue damage with the two-dimensional vortey model is much more serious than that with the one-dimensional vortex model under low frequency ratio.In high frequency ratio range,with the increase of frequency ratio,the influence of cross-flow vibration is more and more obvious on the fatigue in in-line direction.

关 键 词：顶张式立管 涡激振动 两向自由度 疲劳 动力分析 

分 类 号：TU311.1[建筑科学—结构工程]