计及平台垂荡的立管涡激振动模拟与试验验证
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摘要
针对顶端平台垂荡运动与涡激振动联合作用下顶张式立管动力响应预报问题,提出了一套可供选择的时域数值模拟方法.涡激振动模拟基于流体力分解模型,流体力系数库来源于受迫振荡试验数据.采用时变轴向张力等效立管顶端平台垂荡运动对结构动力响应的影响效应,在每一分析步内根据实时轴向张力更新结构刚度矩阵.最新公布的某2.552 m立管模型试验结果用于验证推荐数值方法在顶张力恒定及时变条件下的有效性,预报结果与试验观测吻合度较高.针对数值模拟与模型试验对比研究中发现的亚谐振响应、非对称振型及Mathieu型共振等现象,进行了深入研究并给出相应解释.
An alternative time domain numerical simulation approach is proposed to predict top-tensioned risers' dynamic response under combined action of top-end platform heave motion and vortex-induced vibration(VIV). The VIV simulation is based on force-decomposed model, and hydrodynamic force coefficient database originates from forced vibration experimental data. The time-varying axial tension is adopted, and the platform heave motion effect on structural response is taken into account, and structural stiffness matrix is updated at each time step according to the variation of axial tension. A newly published 2.552 m riser model test is utilized to validate the proposed numerical approach under constant and time-varying top-end tension situations, and the predicted results based on the numerical model show a good agreement with test observations. For the sub-harmonics response, asymmetrical vibration shape and Mathieu-type resonance phenomena captured in the comparisons between numerical and experimental results, further researches are carried out and the corresponding essential explanations are given as well.
An alternative time domain numerical simulation approach is proposed to predict top-tensioned risers' dynamic response under combined action of top-end platform heave motion and vortex-induced vibration(VIV). The VIV simulation is based on force-decomposed model, and hydrodynamic force coefficient database originates from forced vibration experimental data. The time-varying axial tension is adopted, and the platform heave motion effect on structural response is taken into account, and structural stiffness matrix is updated at each time step according to the variation of axial tension. A newly published 2.552 m riser model test is utilized to validate the proposed numerical approach under constant and time-varying top-end tension situations, and the predicted results based on the numerical model show a good agreement with test observations. For the sub-harmonics response, asymmetrical vibration shape and Mathieu-type resonance phenomena captured in the comparisons between numerical and experimental results, further researches are carried out and the corresponding essential explanations are given as well.
引文
[1] FRANZINI G R,PESCE C P,GONCALVES R T,et al.Experimental investigations on Vortex-Induced Vibrations with a long flexible cylinder.Part II:Effect of axial motion excitation in a vertical configuration [C]//Proceedings of the 11th International Conference on Flow-Induced Vibration.Hague,The Netherlands:FIV Committee,2016:1-8.
[2] JOSEFSSON P M,DALTON C.Vortex-Induced Vibration of a variable tension riser [C]//Proceedings of the 26th International Conference on Offshore Mechanics and Arctic Engineering.San Diego,California,USA:ASME Committee,2007:1-13.
[3] 王东耀,凌国灿.在平台振荡条件下TLP张力腿的涡激非线性响应 [J].海洋学报,1998,20(3):119-128.WANG Dongyao,LING Guocan.Vortex-induced nonlinear vibration of TLP tethers under circumstances of platform oscillation [J].Acta Oceanologica Sinica,1998,20(3):119-128.
[4] DA SILVEIRA L M Y,MARTINS C D A,LEANDRO D C,et al.An investigation on the effect of tension variation on VIV of risers [C]//Proceedings of the 26th International Conference on Offshore Mechanics and Arctic Engineering.San Diego,California,USA:ASME Committee,2007:1-9.
[5] 唐友刚,邵卫东,张杰,等.深海顶张力立管参激-涡激耦合振动响应分析 [J].工程力学,2013,30(5):282-286.TANG Yougang,SHAO Weidong,ZHANG Jie,et al.Dynamic response analysis for coupled parametric vibration and vortex-induced vibration of top-tensioned riser in deep-sea [J].Engineering Mechanics,2013,30(5):282-286.
[6] 吴学敏.考虑大变形的深水立管涡激振动非线性分析方法研究 [D].青岛:中国海洋大学,2013.WU Xuemin.Study on non-linear analysis method on VIV of deepwater risers with large deflection [D].Qingdao:Ocean University of China,2013.
[7] CHEN W M,LI M,GUO S X,et al.Dynamic ana-lysis of coupling between floating top-end heave and riser’s vortex-induced vibration by using finite element simulations [J].Applied Ocean Research,2014,48:1-9.
[8] LIE H.A time domain model for simulation of vortex induced vibrations on a cable [C]//Proceedings of 6th International Conference on Flow Induced Vibrations.London,UK:FIV Committee,1995:455-466.
[9] SIDARTA D E,FINN L D,MAHER J.Time domain FEA for riser VIV analysis [C]//Proceedings of the ASME 2010 29th International Conference on Ocean,Offshore and Arctic Engineering.Shanghai,China:ASME Committee,2010:1-14.
[10] WANG K P,XUE H X,TANG W Y.Time domain analysis approach for riser vortex-induced vibration based on forced vibration test data [C]//Proceedings of the ASME 2013 32nd International Conference on Ocean,Offshore and Arctic Engineering.Nantes,France:ASME Committee,2013:1-8.
[11] GOPALKRISHNAN R.Vortex induced forces on oscillating bluff cylinders [D].Doctoral thesis,Cambridge:Massachusetts Institute of Technology,1993.
[12] ZHENG H N.The influence of high harmonic force on fatigue life and its prediction via coupled inline-crossflow VIV modeling [D].Doctoral thesis,Cambridge:Massachusetts Institute of Technology,2014.
[13] VENUGOPAL M.Damping and response of a flexible cylinder in a current [D].Doctoral thesis,Cambridge:Massachusetts Institute of Technology,1996.
[14] HILBER H M,HUGHES T J R,TAYLOR R L.Improved numerical dissipation for time integration algorithms in structural dynamics [J].Earthquake Engineering and Structural Dynamics,1977,5(3):283-292.
[15] FRANZINI G R,PESCE C P,SALLES R,et al.Experimental analysis of a vertical and flexible cylinder in water:Response to top motion excitation and parametric resonance [J].Journal of Vibration and Acoustics,2015,137(3):031010.
[2] JOSEFSSON P M,DALTON C.Vortex-Induced Vibration of a variable tension riser [C]//Proceedings of the 26th International Conference on Offshore Mechanics and Arctic Engineering.San Diego,California,USA:ASME Committee,2007:1-13.
[3] 王东耀,凌国灿.在平台振荡条件下TLP张力腿的涡激非线性响应 [J].海洋学报,1998,20(3):119-128.WANG Dongyao,LING Guocan.Vortex-induced nonlinear vibration of TLP tethers under circumstances of platform oscillation [J].Acta Oceanologica Sinica,1998,20(3):119-128.
[4] DA SILVEIRA L M Y,MARTINS C D A,LEANDRO D C,et al.An investigation on the effect of tension variation on VIV of risers [C]//Proceedings of the 26th International Conference on Offshore Mechanics and Arctic Engineering.San Diego,California,USA:ASME Committee,2007:1-9.
[5] 唐友刚,邵卫东,张杰,等.深海顶张力立管参激-涡激耦合振动响应分析 [J].工程力学,2013,30(5):282-286.TANG Yougang,SHAO Weidong,ZHANG Jie,et al.Dynamic response analysis for coupled parametric vibration and vortex-induced vibration of top-tensioned riser in deep-sea [J].Engineering Mechanics,2013,30(5):282-286.
[6] 吴学敏.考虑大变形的深水立管涡激振动非线性分析方法研究 [D].青岛:中国海洋大学,2013.WU Xuemin.Study on non-linear analysis method on VIV of deepwater risers with large deflection [D].Qingdao:Ocean University of China,2013.
[7] CHEN W M,LI M,GUO S X,et al.Dynamic ana-lysis of coupling between floating top-end heave and riser’s vortex-induced vibration by using finite element simulations [J].Applied Ocean Research,2014,48:1-9.
[8] LIE H.A time domain model for simulation of vortex induced vibrations on a cable [C]//Proceedings of 6th International Conference on Flow Induced Vibrations.London,UK:FIV Committee,1995:455-466.
[9] SIDARTA D E,FINN L D,MAHER J.Time domain FEA for riser VIV analysis [C]//Proceedings of the ASME 2010 29th International Conference on Ocean,Offshore and Arctic Engineering.Shanghai,China:ASME Committee,2010:1-14.
[10] WANG K P,XUE H X,TANG W Y.Time domain analysis approach for riser vortex-induced vibration based on forced vibration test data [C]//Proceedings of the ASME 2013 32nd International Conference on Ocean,Offshore and Arctic Engineering.Nantes,France:ASME Committee,2013:1-8.
[11] GOPALKRISHNAN R.Vortex induced forces on oscillating bluff cylinders [D].Doctoral thesis,Cambridge:Massachusetts Institute of Technology,1993.
[12] ZHENG H N.The influence of high harmonic force on fatigue life and its prediction via coupled inline-crossflow VIV modeling [D].Doctoral thesis,Cambridge:Massachusetts Institute of Technology,2014.
[13] VENUGOPAL M.Damping and response of a flexible cylinder in a current [D].Doctoral thesis,Cambridge:Massachusetts Institute of Technology,1996.
[14] HILBER H M,HUGHES T J R,TAYLOR R L.Improved numerical dissipation for time integration algorithms in structural dynamics [J].Earthquake Engineering and Structural Dynamics,1977,5(3):283-292.
[15] FRANZINI G R,PESCE C P,SALLES R,et al.Experimental analysis of a vertical and flexible cylinder in water:Response to top motion excitation and parametric resonance [J].Journal of Vibration and Acoustics,2015,137(3):031010.