输液管道热膨胀状态下的超临界振动

The super critical vibration of the fluid-conveying pipe in the thermal expansion

应用工程实践中常用的Euler梁模型,研究在热膨胀作用下,随着液体流速的加快,输液管道的屈曲变形和固有频率的变化情况。通过Hamilton原理推导出输液管道的曲线平衡位形微分方程,并分析了热膨胀对输液管屈曲构型的影响。通过伽辽金(Galerkin)离散方法,得到了在热膨胀作用和液体流速达到超临界时,输液管道一阶固有频率的解析解。对比在液体流速达到超临界时,热膨胀对输液管道屈曲变形和一阶固有频率的影响。

The paper dealt with the variation on buckling distortion and natural frequency of the fluid - conveying pipe subjected to thermal expansion with the acceleration of the fluid velocity by using Euler beams model applied in engineering practice. The curve equilibrium differential equation of the fluid-conveying pipe was deduced by Hamilton principle, and the buckling deformation of the fluid-conveying pipe under thermal expansion was analyzed. By using the Galerkin Discretization method, the analytical solution to the first-or- der natural frequency of the fluid-conveying pipe in thermal expansion was obtained when the flow speed of fluid exceeded the critical value. Thermal expansion of the fluid-conveying pipe affected the buckling configurations and the first-order natural frequency of the pipe, which was compared with that of corresponding flow speed of the fluid-conveying pipe reaching the super-critical value.