Euler-Bernoulli海洋立管涡致强迫振动响应研究

Vortex Induced Forced Vibration of Euler-Bernoulli Pipe-in-pipe System

赵翔 谭明 李映辉 邵永波

ZHAOXiang TANMing LIYinghui SHAOYongbo

西南石油大学土木工程与测绘学院, 四川 成都 610500 西南交通大学力学与工程学院, 四川 成都 610031

School of Civil Engineering and Geomatics, Southwest Petroleum University, Chengdu, Sichuan 610500, China School of Applied Mechanics and Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, China

针对海洋立管（Pipe-in-pipe，PIP）系统在海水作用下发生的振动问题，开展了对PIP系统在涡致强迫振动下的动力学响应研究，分析了在涡致强迫振动下海洋立管外管直径、轴向拉力、外激力频率对海洋立管位移响应的影响规律。基于Euler-Bernoulli双梁模型，采用Lamb-Oseen涡模型，建立了动力学模型，利用格林函数法求得该强迫振动的稳态响应。结果表明，随着管道直径增加，外激力增加，产生最大力幅值的位置离管道越远；轴向拉力对外部管道的影响较大，对内部管道的影响较小；无因次频率取0.4时，外部管道位移超出允许变形极限，内外管壁发生周期碰撞，易对海洋立管造成损伤。

In order to solve the vibration problem of a Pipe-in-pipe (PIP) system under the action of seawater, the dynamic response of the vortex induced forced vibration of the PIP system is studied. Then the numerical analysis is carried out to study influences of the outer pipe diameter, axial load, and external excitation frequency on displacement responses of the PIP system under the action of vortex. Based on Euler-Bernoulli beams theory, Lamb-Oseen vortex model is used to establish the dynamic model the PIP system, and Green function method is used to obtain the steady-state response of the forced vibration of the PIP system. Results show that as the diameter of the outer pipe increases, the vortex excitation force increases, and the position of the maximum amplitude becomes farther from the outer pipe; the axial tension has a greater impact on the outer pipe, but has a smaller effect on the inner pipe; when the dimensionless external excitation frequency sets to 0.4, the displacement of the outer pipe exceeds the limit of allowable deformation, and periodic collisions between the inner and outer pipe can easily happen, which cause damage to the PIP system.

10.11885/j.issn.1674-5086.2021.02.23.01