随机荷载下陡波形立管的非线性动力分析EI北大核心CSCD

对陡波形立管在随机荷载作用下的非线性动力响应进行了数值分析。考虑内部流体,基于柔性杆理论建立了陡波形立管(SWR)的数值模型,采用Newmark-β法求解立管动力响应,利用MATLAB软件编写相应计算程序DRSWR,将DRSWR的计算结果与OrcaFlex进行对比验证,然后对陡波形立管在随机波浪、顶部浮体随机运动共同激励下的应力响应进行了参数敏感性分析。结果表明:浮子段应力水平、应力变化幅值最高;应力极值点为拱弯点和垂弯点;大波高、低周期的波浪会导致立管整体应力水平急剧升高;平均静偏移增大导致立管应力极值减小;大幅高频的慢漂运动会使悬挂点应力显著增大;高密度、高流速内部流体会使陡波形立管处于高应力状态。

Nonlinear dynamic analysis of SWR under random load

Here,the nonlinear dynamic response of steep wave riser(SWR)under random load was numerically analyzed.Considering internal fluid,the numerical model of SWR was established based on the flexible rod theory.The Newmark-βmethod was adopted to solve the dynamic response of SWR,and the corresponding calculation program DRSWR was compiled with MATLAB.The calculation results of DRSWR were compared with those of OrcaFlex for verification,and then the parametric sensitivity analysis for the stress response of SWR under the combined excitation of random wave and random motion of top floating body was performed.The results showed that stress level and stress variation amplitude of the buoyancy section are the highest;extreme value points of stress are arc bend point and sag bend point;large waves with high significant wave height and low periods can cause a sharp increase in the overall stress level of SWR;increase in mean offset leads to decrease in extreme values of riser stress;large amplitude and high frequency slow drift motion can significantly increase the stress at the hang off point;high density and high flow velocity internal fluid can make SWR be in a high stress state.