【摘要】 考虑流体与曲管的相互作用 ,利用虚功原理导出了输液曲管振动问题的有限元格式。为了提高精度 ,文中还提出了一个具有 7自由度的特殊曲管元。对于自激振动问题 ,通过特征值求解 ,求出了输液曲管发生颤振失稳时的临界流速。对于动力响应问题 ,通过引入伴随系统实现方程的解耦 ,可把输液曲管这类非经典系统化成单自由度问题求解。实例表明提出的单元形式有很好的精度更多还原

【Abstract】 Based on the virtual work principle and interaction between fluid flow and curved pipe,we derive a refined finite element form of curved pipes conveying fluid problem,in which a special curved pipe element with seven degree of freedom is constructed.For a self excited vibration problem,the critical velocities of curved cantilever pipes conveying fluid are obtained by the present method.For the dynamic response problem,this paper proposed a new modal analysis method that doesn′t need to possess any of the familiar properties such as symmetry or definiteness of the coefficient matrixes in the governing equation of pipe conveying fluid.So it can be widely used in non classical system.Those expamples show that the element form proposed has a great accuracy.更多还原