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 Considering the interaction between the fluid and the bent pipe, the finite element method of the vibration problem of the bent pipe is derived using the principle of virtual work. In order to improve the accuracy, a special curved pipe element with 7 degrees of freedom is also proposed in this paper. For the problem of self-excited vibration, the eigenvalue is used to find the critical flow rate when the flutter buckling occurs in the infusion bent pipe. For the dynamic response problem, by introducing the decoupling of the system realization equation, we can solve the non-canonical system of the transfusion bent pipe into a single degree of freedom problem. The examples show that the proposed unit form has good accuracy