摘要
大跨度柔性悬跨海管的振动响应及管床碰撞会加剧管道的疲劳损伤,影响管道油气的安全输运。基于高速摄像非介入测试方法捕捉了近底床柔性悬跨海管的振动响应特征及管床拍击过程,对比分析了间隙比G/D及约化速度U_(r)对振动—拍击耦合响应的影响,辨识并提出了试验观测的管床拍击模式。研究结果表明:悬跨管的均方根振幅A_(z,rms)/D在前二阶主导模态下随约化速度U_(r)的升高先增大后减小;当间隙比减小时,共振区的振动频率减小,且一阶振动向二阶振动的过渡在更高的约化速度时发生,过渡时存在时间上的模态切换现象。振动平衡位置向远离壁面一侧偏移。根据悬跨管振动的主导模态与拍击特性,通过试验辨识了6种管—床拍击模式,包括一阶模态主导的小段拍击、大段拍击,一阶向二阶模态过渡时的Ⅰ、Ⅱ型拍击,以及二阶模态主导的单段拍击、双段交替拍击。
Vortex-induced vibration and pipe-wall impact may aggravate the fatigue damage of a flexible submarine span with a large aspect ratio,affecting the oil-gas transportation.A non-intrusive measurement with two high-speed cameras was employed in this research to capture the vibration displacement and the pipe-wall impact instants.The effects of gap ratio G/D and reduced velocity U_(r) on the vibration-impact interaction were examined,and the pipe-wall impact patterns were identified.The results show that the root-mean-square amplitude A_(z,rms)/D experiences the first rise and then decreases with the increase of U_(r) for the first two modes.The vibration frequency in the lock-in region reduces as gap ratio decreases,and the mode transition from the first mode to the second one occurs at a higher reduced velocity.Additionally,mode switches over time during the transition.The new equilibrium position offsets from the wall boundary.Six distinct pipe-wall impact patterns are identified in terms of the dominant mode and the solid collision characteristics,including the first-mode dominant response with short segment impact,the first-mode dominant response with long segment impact,transition mode Ⅰ,transition mode Ⅱ,the second-mode dominant response with a single segment impact,and the second-mode dominant response with two alternative segment impacts.
作者
朱红钧
赵宏磊
谢宜蒲
张旭
ZHU Hongjun;ZHAO Honglei;XIE Yipu;ZHANG Xu(Petroleum Engineering School,Southwest Petroleum University,Chengdu 610500,China)
出处
《海洋工程》
CSCD
北大核心
2022年第5期1-9,共9页
The Ocean Engineering
基金
国家自然科学基金面上项目(51979238)。
关键词
涡激振动
柔性悬跨海管
管床拍击
主振模态
拍击模式
vortex-induced vibration
submarine flexible span
pipe-wall impact
dominant vibration mode
wall-impact pattern
作者简介
朱红钧(1983-),男,江苏靖江人,教授,博士生导师,主要从事海洋多场多相耦合力学研究。E-mail:ticky863@126.com。
