In consideration of the effect of the internal flowing fluid and the external marine environmental condition on the vortex-induced vibration （VIV） of top tensioned riser （Till）, the differential equation is derive...In consideration of the effect of the internal flowing fluid and the external marine environmental condition on the vortex-induced vibration （VIV） of top tensioned riser （Till）, the differential equation is derived based on work-energy principles and the riser near wake dynamics is modeled by Facchinetti＇ s wake oscillator model. Then Galerkin＇ s finite element approximation is implemented to derive the nonlinear matrix equation of the coupled equations and file corresponding numerical programs are compiled which solve the coupled equations directly in the time domain. The comparison of the predicted results with the recent experimental results and the prediction of SHEAR7 is performed. The results show the validity of the proposed method on the prediction of VIV of deep water risers. The effect of internal flow on the dynamic characteristics and dynmnic response of the riser is analyzed and several valuable conelusions are drawn.展开更多
建立了轨道车辆“惯容器-弹簧-阻尼”(Inerter Spring Damper,ISD)悬挂结构垂向振动的动力学模型,采用强迫振动理论进行了振动响应特性以及隔振性能分析。研究发现:ISD结构的振幅、振幅放大因子、速度放大因子和加速度放大因子相对质量...建立了轨道车辆“惯容器-弹簧-阻尼”(Inerter Spring Damper,ISD)悬挂结构垂向振动的动力学模型,采用强迫振动理论进行了振动响应特性以及隔振性能分析。研究发现:ISD结构的振幅、振幅放大因子、速度放大因子和加速度放大因子相对质量比存在极小值点,此最优质量比是频率比和阻尼比的函数;阻尼比和质量比建议取值范围为ξ<0.2及0.1<μ<0.3,此时隔振性能可得到最大程度提升;质量比越大,相位差越小。推导了临界频率比、共振点频率比与质量比的关系,质量比越大,临界频率比和共振点频率比越小,共振点处的振幅放大因子以及共振区宽度也明显减小。该结果对轨道车辆ISD悬挂结构的减隔振性能分析和轻量化研究提供了一种新的思路,并对ISD结构设计中关键参数的选取提供了参考。展开更多
基金supported by the National High Technology Research and Development Program of China(863 Program,Grant No.2006AA09Z356 and No.2007AA09Z313)
文摘In consideration of the effect of the internal flowing fluid and the external marine environmental condition on the vortex-induced vibration （VIV） of top tensioned riser （Till）, the differential equation is derived based on work-energy principles and the riser near wake dynamics is modeled by Facchinetti＇ s wake oscillator model. Then Galerkin＇ s finite element approximation is implemented to derive the nonlinear matrix equation of the coupled equations and file corresponding numerical programs are compiled which solve the coupled equations directly in the time domain. The comparison of the predicted results with the recent experimental results and the prediction of SHEAR7 is performed. The results show the validity of the proposed method on the prediction of VIV of deep water risers. The effect of internal flow on the dynamic characteristics and dynmnic response of the riser is analyzed and several valuable conelusions are drawn.
文摘建立了轨道车辆“惯容器-弹簧-阻尼”(Inerter Spring Damper,ISD)悬挂结构垂向振动的动力学模型,采用强迫振动理论进行了振动响应特性以及隔振性能分析。研究发现:ISD结构的振幅、振幅放大因子、速度放大因子和加速度放大因子相对质量比存在极小值点,此最优质量比是频率比和阻尼比的函数;阻尼比和质量比建议取值范围为ξ<0.2及0.1<μ<0.3,此时隔振性能可得到最大程度提升;质量比越大,相位差越小。推导了临界频率比、共振点频率比与质量比的关系,质量比越大,临界频率比和共振点频率比越小,共振点处的振幅放大因子以及共振区宽度也明显减小。该结果对轨道车辆ISD悬挂结构的减隔振性能分析和轻量化研究提供了一种新的思路,并对ISD结构设计中关键参数的选取提供了参考。
