摘要
将变参数受拉柔性梁的有限元模态分析与涡激振动预报结合在一起,建立了变参数柔性立管的横向涡激振动预报模型,考虑到海洋立管的模态信息与涡激振动响应高度耦合,为合理计算附加质量对模态信息的影响,模态分析与涡激振动响应预报迭代进行.其中,使用有限元方法对立管进行模态分析,考虑了质量、拉力、抗弯刚度沿立管轴向的变化;在此基础上,涡激振动响应计算在各个模态上分别进行.在出现多模态参与的情况时,比较各模态的振幅,对模态受力进行折减.与近期阶梯状来流作用下立管涡激振动实验结果的比较显示,本文模型是有效的.
Based on the data from forced vibration experiments with cylinder section, a prediction model was developed for vortex-induced vibration （VIV） in transverse direction of a riser with varying tension, flexural rigidity and mass density. The VIV response of a marine riser is highly coupled with its modal shape and modal frequency. In order to properly take account of the added mass effects, the modal analysis with finite element method is integrated into VIV prediction process. So that the modal frequencies, shape and added mass are calculated in an iterative way. The proposed model has fewer assumptions than other existing VIV prediction code except that reduction in modal excitation force is applied when multi-mode response occurs. The comparison with the recent experiment carried out by Chaplin et al on a vertical tension riser in stepped current shows the validity of the proposed model.
出处
《上海交通大学学报》
EI
CAS
CSCD
北大核心
2006年第6期1064-1068,共5页
Journal of Shanghai Jiaotong University
基金
国家自然科学基金资助项目(50323004)
上海市科委专项基金项目(05DG14001)
关键词
涡激振动
立管
模态分析
多模态响应
响应预报
vortex-induced vibration （VIV）
riser
modal analysis
multi-mode response
response prediction
