传输管道流固耦合振动的模态分析

 通过线性化假设，并进行Ｌａｐｌａｃｅ变换，导出了流体的流量、压力与管道的应力及位移之间的网络模型，通过求解特征根和特征向量建立起其传递矩阵，在该模型的建立中，首次考虑了频率相关摩擦项的影响，对仿真精度有较大的提高。另外在空间管的节点耦合中，给出了两次坐标变换的方法，解决了空间管道的通用耦合算法，甚至可用于空间曲线管路的近似计算。大量的试验结果与仿真结果的比较证明了该方法的正确性。

FREQUENCY DOMAIN ANALYSIS OF VIBRATIONS IN LIQUID FILLED PIPING SYSTEMS

In the analysis of the liquid filled piping systems there are Poisson coupled axial stress waves in the pipe and liquid column, which is caused by the dilation of the pipe. In some conditions, the influence of viscous friction that is usually frequency dependent should not be omitted, which in fact is another kind of coupled form. It directly influences the amplitude of vibration of piping systems to some degrees. The larger the viscosity of liquid is, the greater the influence will be. The present paper will give detail solutions to the transfer matrix that represents the motion of the single pipe section, which is the basis of complex fluid structure interaction analysis. Combined with point matrices that describe specified boundary conditions, the overall transfer matrix for a piping system can be assembled. Corresponding state vectors can then be evaluated to predict the piping and liquid motion. At last, the twice coordinate transformation method is adopted in joint coupling. Consequently, the vibration analysis of spatial liquid filled piping systems can be carried out. It is proved to be succinct, valid and versatile. This method can be extended to the simulation of the curved spatial pipeline systems.