多跨输液管的稳定性及动力响应

STABILITY AND DYNAMIC RESPONSE OF MULTI SPAN FLUID CONVEYING PIPES

本文研究了在工程中常见的支承在多个弹性支座上的输液管系，用Ｈａｍｉｌｔｏｎ原理和有限元法建立管道系统的运动方程，通过求解带有陀螺矩阵的振动方程组的特征值问题计算了这种管系的临界流速，结果表明，前两阶模态的临界流速相同，且明显高于单跨管的最低临界流速；用威尔逊－θ逐步积分法考察了管系在临界流速附近对扰动的响应，结果表明，当小于临界流速时，响应主要是低频周期振动；反之。

Fluid conveying pipe system resting on elastic supports,commonly used in industry is investegated. Hamilton energy theorem and FEM method are used to formulate the vibration equations of the pipe system. The eigensolution of the equations characterized by a gyroscopic matrix gives the critical velocity of the pipe system. Numerical result shows that the first two order critical velocities are the same and apparently larger than the first order critical velocity of singlespan pipe. The structure dynamic responses under a moment pulse near critical velocity are also found by numerical integral Wilson θ method. The result shows that when the velocity is less than the critical one, the displacement rosponse is periodical mainly in low frenquency; on the contrary, it increases exponentially with time increasing.