不同边界条件下输流曲管的振动特性

Vibration Characteristics of Fluid-Conveying Curved Pipe under Different Boundary Conditions

提出了细长输流曲管边界条件的一种通用处理方法。通过约束刚度来控制边界条件,利用微分求积法和分块矩阵法处理不同边界条件下轴向可伸长输流管道的控制运动方程,采用双步QR法求解输流管道的固有频率和临界流速。对初始构型有缺陷的输流直管和输流曲管振动特性展开研究,并分析输流管道几何参数对稳定性的影响。数值结果表明,输流管道固有频率随着约束刚度值的增加而增大;对于初始构型有缺陷的输流管道,构型缺陷幅值微小的变化会造成输流管道临界流速和固有频率较大的变化。这项研究在工程应用中有十分重要的实际参考价值。

A general approach addressing the issue of boundary conditions of slender fluid-conveying curved pipe is proposed.Constraining stiffness is utilized to control the boundary conditions.The differential quadrature method and partitioned matrix method are employed to deal with governing equations of motion of the axial extensible fluid-conveying pipe under different boundary conditions.The double-step QR method is adopted to solve the natural frequencies and critical velocity of the fluid-conveying pipe.Vibration analysis is conducted for both straight pipe and curved pipe with initial configuration imperfection.The influence of geometric parameters on stability of fluid-conveying pipe is investigated as well.Numerical results show that natural frequencies of fluid-conveying pipe rise with the increasing of constraining stiffness.And a small change in the initial configuration imperfection can affect the critical velocity and natural frequencies of fluid-conveying pipe greatly.This study can provide significant reference for the engineering applications.