考虑温度应力的海洋输液立管动力特性及涡激振动研究

考虑海洋立管管内外温差产生的温度应力以及管内流动流体和管外海洋环境荷载共同作用,建立了立管的涡激振动微分方程,采用伽辽金法对输液立管的动力特性进行分析,给出了有管内流体和温度应力时的海洋立管动力特性的表达式。结合典型平台输油立管的设计参数,分析了在百年一遇海况条件下立管的涡激振动状态和振动幅值。管内流体流动和管内外温差会降低立管的固有频率。对于有可能发生锁频共振的管段,应该采取一定的措施予以避免。

Study on dynamic characteristics and vortex-induced vibration of marine risers considering temperature stress

Considering the temperature stress induced by temperature difference between inside and outside the marine riser as well as the joint effect of the internal flowing fluid and the external marine environmental loads,the differential equation for the vortex-induced vibration of marine riser is established;the dynamic characteristics of the riser is analyzed by Galerkin method and a represent of dynamic characteristics of the riser with internal fluid and temperature stress is suggested.Combining the pipeline riser design data of typical platforms,the status and responses of the vortex-induced vibration of the marine risers under the sea condition of 100 years return period are analyzed.Natural frequency of the riser will decrease due to the internal fluid flowing and temperature differential.For pipe section where frequency-locking resonance maybe occur,a certain measures should be taken to avoid such event.