海洋立管涡激振动位移响应测试方法及试验研究

Dispacement Respontse Testing and Experimental Investigation for VIV of Marine Risers

海洋立管涡激振动会使立管产生疲劳破坏。实时监测应变并通过应变数据转化为立管的位移,从而可直观、准确地判断海洋立管的状态,预知可能发生破坏的位置并采取应对措施。建立了数学模型,通过理论分析立管的挠度曲率与应变、位移存在的关系,进而拟合立管的挠度曲线。基于挠度曲线的边界条件以及广义最小二乘法确定挠度曲线未知数的求解方法。设计试验方案,搭建试验平台,通过光纤光栅应变传感器及解调仪获得试验数据,求解挠度曲线。并通过试验过程中位移的测量值来验证位移计算值的正确性及可行性,试验结果表明:位移的计算值精度能够满足工程上的要求,该方法可作为检测立管涡激振动的一种方法。

The vortex-induced vibration （VIV） of marine riser causes fatigue failure of risers. Real-time monitoring strain and translating the data of strain into the displacement could accurately show the state of the ocean riser, whichhelps to predict the location of possible damage and take measures to deal with it. First, the relationship between the curvature of the vertical tube and the strain and displacement is analyzed by establishing mathematical model. The researchers try to determine the unknown quantity of the deflection curve based on the boundary condition of deflection curve and generalized least square method. Designing test plan, setting up test platform and obtaining data by Fiber Bragg grating strain sensor and demodulation instrument can get deflection curve. Through the test method, comparison of the calculated values and the calculated values of the displacement, the correctness and feasibility of the calculated value can be verified. Test results show that the accuracy of the calculated value of dis- placement can meet the engineering requirements, whichprovesthat this method can be used to detect the vortex induced vibration.