基于钢悬链式立管(SCR)动力分析程序CABLE3D,采用大挠度柔性梁理论建立SCR的运动方程,将线性海床模型扩展为考虑海床土吸力的非线性海床模型,采用非线性有限元方法对控制方程进行离散,时域内积分采用Newmark-β法,开发出新的计算程序。通过算例分析上部浮体垂荡运动幅值、海床土剪切强度、海床土剪切强度梯度对SCR触地点区域动力响应和疲劳损伤的影响。分析结果表明:SCR触地点区域动力响应和疲劳损伤对上部浮体垂荡运动幅值和海床土剪切强度的变化较为敏感,疲劳损伤在触地点区域最大,远大于悬垂段和流线段,在设计过程中应采取一定的加强措施。
Based on the Steel Catenary Riser dynamic analysis program-CABLE3D, this paper extended the linear elastic support on the seabed to nonlinear riser-soil interaction, by considering the influence of soil suction. Control equations were discretized by nonlinear finite element method, and Newmar-13 method was used in the time domain numerical integration. By discussing the influence of floating structure motion amplitude, soil shearing intensity, soil shearing intensity gradient on dynamic response and fatigue damage of SCR at TDZ, the result shows that the dynamic response and fatigue damage of SCR is sensitive to floating structure motion amplitude and soil shearing intensity. The maximum fatigue damage occurs at Touch Down Point, and should be noted.