三类边界条件下隔水套管涡激非线性振动的分析研究

考虑流及波流联合作用,研究了套管的涡激非线性振动.将套管简化为梁模型,考虑3类不同的边界条件,计及莫里森非线性流体动力和涡激荷载,建立套管的涡激振动方程.应用克雷洛夫函数求解套管的固有频率和模态,采用了计算涡激非线性动力响应的迦辽金方法.以东海勘探3号钻井隔水套管为例,研究了不同边界条件下流引起的主共振和波流联合引起的组合共振.计算结果表明:流对套管的动力响应占主导地位,而波的影响不大.分析了3类不同边界条件下隔水套管的涡激非线性动力响应,揭示了波流联合激励下套管复杂的动力响应特性.

Comparative Analysis of Vortex Induced Nonlinear Vibration of Casing Pipe under Three Different Boundary Conditions

The casing pipes are widely used for drilling wells in the ocean.But less investigation on VIV excited by wave-current combination was done for casing pipes in the deep water.In this paper,the vortex-induced nonlinear vibration of casing pipes in deep water was studied considering the loads of current and combined wave-current.The vortex-induced vibration equation of casing pipes was set up with considering the beam mode and Morison's nonlinear fluid damp as well as the vortex-excited loads under three different boundary conditions.The vortex-excited nonlinear vibration was calculated by using Galerkin's method.The response including primary resonance induced by current and the composite resonance under combined wave-current for the marine drilling risers of the Donghai 3 were studied.The numerical results show that the dynamic response of marine risers induced by the current is basic and the influence of wave may be neglected.The vortex-induced nonlinear vibration of casing pipes under three different boundary conditions is studied and the complicated response behaviors of casing pipes are described under combined wave-current based on the numerical simulations.