钢质悬链线式立管的涡激疲劳损伤是影响其寿命的主要因素之一.文中将悬链线立管简化为忽略剪切力的索模型,对悬链线立管进行模态分析,考虑流体附加质量的影响,得到其在海水下的频率和振型.根据斯托劳哈尔关系和外部流速大小的范围确定潜在的激励模态范围,并通过计算潜在模态的能量确定主要激励模态.根据能量平衡,求出升力系数和阻尼系数,从而计算出立管各阶模态下的模态力和模态阻尼.再利用模态叠加法对悬链线立管进行动力响应分析.并以2 300 m Spar平台的悬链线输油立管为例,计算了其在北海某流速作用下的疲劳损伤,所得结论对工程应用有一定的借鉴意义.
The VIV(Vortex Induced Vibration) induced fatigue damage is one of the prime factors to affect the life time of SCR(Steel Catenary Riser).The SCR was simplified into a cable model when shear force was not considered.Regarding the added mass of the fluid,the modal analysis was carried out for the riser;and then,natural frequencies and corresponding vibration modes were obtained.The potential excited modes were gotten by Strouhal number and flow velocity.Moreover,the main excited modes were decided by their potential modal powers.According to balance of energy,lift coefficient and damping coefficient were obtained.Furthermore,dynamic response of the SCR was studied using modal superposition method.A 2300 m Spar Platform-Riser system of engineering was taken as an example to obtain some useful results for offshore engineering.