平台运动下悬链线立管涡激振动响应特性分析

悬链线立管会在半潜平台运动带动下出现涡激振动现象,对立管疲劳寿命造成影响.借助海工结构物动力分析软件Orcaflex建立立管模型,使用Iwan-Blevins尾流振子模型进行数值模拟.通过与试验结果对比验证了该方法的可行性.同时建立实尺度悬链线立管模型,并考虑背景海流的影响,分析平台垂荡、纵荡运动下的立管涡激振动响应和疲劳损伤.研究表明,平台运动产生的非定常流场将引起悬链线立管发生涡激振动现象,并在背景洋流激励的基础上增大疲劳损伤,在立管结构实际工程设计时应予以关注.

Analysis of VIV Response and Fatigue Characteristics of Steel Catenary Riser under Current and Platform Motion

Driven by the movement of the semi-submersible platform, the steel catenary riser will occur vortex-induced vibration, which can affect the fatigue life. The paper builds a riser model with the help of marine structural dynamic analysis software Orcaflex, and uses Iwan-Blevins wake oscillator model for numerical simulation. The feasibility of the method is verified by comparison with the test results. A real-scale catenary riser model is established to analyze vortex-induced vibration and fatigue damage of the riser under heave and surge motion of the platform, and the influence of the background current is considered. Studies have shown that platform motion will lead to unsteady flow field, which can cause vortex-induced vibration of steel catenary riser and increase the fatigue damage based on background current excitation, so attention should be paid to the engineering design of the riser structure.