基于灰色理论的多参数海洋立管涡激振动试验研究

摘要

The vortex induced vibration of risers with multi-parameters is studied by model experiment.The parameters considered are materials of the riser models,top tensions,boundary conditions and flow velocities.Aluminium,PMMA and UPVC are chosen for the materials;0.2 m/s,0.6 m/s and 1 m/s are selected for the flow velocities;simple-simple (S-S) support and simple-fix (S-F) support are utilized for the boundary conditions;and @@5 N and 65 N are applied as the top tension forces.Dynamic strains of the risers are gotten through the electrical measuring method,and then,the in-line and transverse vibration responses and vortex shedding frequencies of the different risers can be obtained using these dynamic strain data.At last,grey theory is utilized to analyse the effects of the different parameters on the risers' vibration responses.The results showed that the most important parameter for the risers' vortex shedding frequency is the materials of the risers.More specifically,the grey relational order is r01(material) ＞ r02(velocity) ＞ r03(boundary condition) ＞ r04(top-tension),i.e.,the materials of risers,flow velocities and boundary conditions have greater effects on the risers' vortex shedding frequency compared with top-tension forces.%通过模型试验的方法对多参数作用下的海洋立管的涡激振动进行了研究.试验参数包括:立管模型材料、顶张力、边界条件以及流速.模型材料选取了铝(AJ)、有机玻璃(PMMA)和硬质塑料(UPVC)三种;流速采用0.2 m/s、0.6 m/s和1m/s;边界条件采用两端铰接(S-S)和铰接-固接(S-F)两种,顶张力选取为5N和65 N.通过电测法获得动态应变数据,得到立管的顺流向振动响应、横流向振动响应以及漩涡脱落频率;利用灰色理论分析不同参数对立管涡激振动响应的影响.结果表明,立管材料对立管的振动起着主要影响,各参数对漩涡脱落频率的关联序为r01 ＞r02 ＞r03 ＞r04(r01为材料,r02为流速,r03为边界条件,r04为顶张力);即立管材料、流速与边界条件对漩涡脱落频率影响大,顶张力较其他三个因素影响稍弱.