中文摘要：

考虑随机波和阶梯流的联合作用，研究了一座TLP张力腿的涡激非线性振动．将张力腿简化为梁模型，计及Mori-son非线性流体动力和涡激荷载，建立了张力腿涡激振动方程，求解了张力腿的固有频率和模态．采用计算涡激非线性动力响应的Galerkin方法，计算了500m水深下一座TIJP张力腿的前5阶固有频率和模态，研究了波流联合引起的组合共振，计算了动剪力和动弯矩，分析了升力系数和阻力系数对振动的影响，模拟了两种典型海况对张力腿动力响应的影响．结果揭示了随机波和阶梯流联合激励下张力腿复杂的动力响应特性．

英文摘要：

The vortex-induced nonlinear vibration of TLP tethers in the deep water is studied considering the loads of random sea waves and stepped currents. The vortex-induced vibration equation of a tether is set up con- sidering the beam mode and Morison＇ s nonlinear fluid loads as well as the vortex-excited loads. The Galerkin＇ s method is adopted to calculate vortex-excited nonlinear vibration. The first five natural vibration frequencies and modes are obtained, and the composite resonances under combined wave-current for TLP tethers at 500 m depth of water are investigated. Modal bending moments and shear forces are calculated, and the effect of lift coeffi- cient and drag coefficient on the vibration are analyzed. The dynamic responses of two typical sea states to the tethers are simulated. The results show the complicated dynamic response behaviors of TLP tethers excited by stepped currents and random sea waves.