Nonlinear Stability of the Lateral Vibration of a Fluid-Conveying Pipe

本文从理论和实验两方面研究了在超临界条件下，端部有质量的悬挑输流管道的非线性横向振动，即在临界速度以上的内流作用下，管道的平面和非平面振动均为自激振动。从管道横向变形的非线性耦合方程出发，从理论上讨论了端部质量对管道振动的影响。一下用输送水的硅橡胶管进行实验。利用图像处理系统对两台CCD摄像机拍摄的图像进行了处理，观察了输流管道的空间特性，并对管道上端沿水平方向受到周期性激励的情况进行了研究。

In this paper, the nonlinear lateral vibrations of a cantilevered pipe, which is hung vertically with an end mass and conveys fluid, are examined theoretically and experimentally under the supercritical condition that planar and nonplanar pipe vibrations are self-excited due to an internal flow above the critical velocity.First, the effect of an end mass on the pipe vibration is discussed theoretically with the nonlinear coupled equations of the lateral deflections of the pipe. Second. the experiments were conducted with a silicon rubber pipe conveying water. The spatial behaviors of the fluid-conveying pipe were observed by means of the image-processing system based on the images from two CCD cameras.Furthermore it is examined for the case that the upper end of the pipe is excited periodically in a horizontal direction.