悬空输油管道的地震动力反应分析

针对工程中常见的悬空输油管道，考虑地震载荷的作用和输送液体与管道的相互作用，建立数学模型，用Hamilton原理和有限元法推导了管道的固液耦合振动方程。采用Newmark逐步积分法直接求解方程，在不同流速和不同边界条件下，对管道的地震动力响应进行计算。结果表明：管道的固有频率随流速的增大而降低，当固有频率降低至地震频率时，结构发生共振；当流速达到临界流速时，位移随时间按指数增大，固液耦合作用不能忽略。

Dynamic Response Analysis of Suspended Oil-conveying Pipe under Earthquake Load

The suspended oil-conveying pipe commonly used in industry was investigated.Considering the action of an earthquake load and the coupling vibration between oil and the pipe,a mathematic model was established,and the Hamilton principle and finite element method were used to formulate the fluid-structure coupling vibration equation of the pipe.Under the earthquake load,the pipe's dynamic responses with different velocities and different boundary conditions were calculated by the numerical integral Newmark method.The numberical result shows that the natural frequency of the pipe decreases with the increase of the flowing velocity.When the first frequency decreases to the earthquake frequency,the pipe appears resonant.When the flowing velocity is equal to the critical velocity,the displacement increases exponentially over the passage of time.Therefore,the effect of fluid-structure interaction cannot be ignored.