【作者】 王琰；

【导师】 朱海涛； 刘治国；

【作者基本信息】 天津大学 ， 工程（专业学位）， 2022， 硕士

【摘要】 钢悬链线立管内部一般有高压的油或气流过,外部承受波浪、海流作用同时也受到顶部浮体运动的影响。同时考虑外部随机波浪力和顶部浮体激励,才能更准确的分析钢悬链线立管在海洋环境中的动力响应。本文利用哈密顿原理,考虑轴向应变能和弯曲应变能所做的虚功以及重力、惯性力、外部流体作用力和结构阻尼所做虚功,建立适用于计算分析自由悬挂钢悬链线立管的二维动力学数学模型。选取三次Hermit插值函数,利用有限元法得到质量、阻尼和刚度矩阵,通过Newton-Raphson法迭代法来计算立管的位移和转角增量,来确定立管的静力平衡状态。通过求解广义特征值和特征向量,得到立管的自振频率以及模态形状。将浮体运动简化为简谐运动,施加于立管顶端,采用Newmark-β法进行逐步积分,研究不同激励幅值和激励频率对立管应力分布的影响,探讨了顶部浮体激励下内流流速、顶部张力、外流流速和弯曲刚度等影响因素的对立管的动力响应的影响。结果表明,各种因素对于立管的动力响应都有不同程度的影响。假设随机波浪可以用有限个余弦波叠加,选取JONSWAP波浪谱和Longuet-Higgins模型通过频谱表达式来模拟随机波得到可以用于计算的随机波浪力,对同时施加顶部浮体简谐激励和随机波浪力的立管进行动力分析,选取了多种工况进一步分析讨论了立管在不同有义波高和谱峰周期作用下的动力响应变化。结果表明,大波高低周期的波浪力会显著增加立管的动力响应。更多还原

【Abstract】 The steel catenary riser is generally subjected to high-pressure oil or airflow inside and is also affected by waves and the top floating motion.The dynamic response of steel catenary risers in marine environment can be more accurately analyzed by considering external random wave force and top floating body excitation.Based on the Hamilton principle,considering the virtual power caused by axial strain and bending strain energy as well as the virtual power caused by gravity,inertial force,external fluid force and structural damping,a two-dimensional dynamic mathematical model is established for the use of the calculation and analysis of SCR.Select three Hermit interpolation functions,use the finite element method to obtain quality,damping and stiffness matrix,and calculate the displacement and corner increments of the steel catenary riser by Newton-Raphson method to get the static balance of the riser.By solving the extensive characteristic value and feature vectors,the natural frequency and modular shape are obtained.Simplifying the floating body motion into a piercing movement,applied to the top of the riser,and uses the Newmark-β method to gradually integrate,studying the impact of different excitation amplitude and excitation frequency on the stress distribution of the tube,and discussing the internal flow rate of the top floating body.The effect of the dynamic response of the effect of top tension,outflow flow rate and bending strength.The results show that the dynamic response of various factors has different degrees of power response.Assuming that the random wave can be superimposed with a limited cosine wave,select the JONWAPS Waves and longuet-Higgins models to simulate random waves by spectral expressions to get random waves can be used to calculate,to simultaneously apply top floating body harmonics and random wavy The riser is dynamically analyzed,and a variety of working conditions are selected to discuss the dynamic response of the riser under different wave height and peak cycle.The results show that the dynamic response of the riser can be significantly increased by the big wave height and low cycle.更多还原