关键词: 振动与波, 管道, 流固耦合, 动力特性, 模态

Abstract:

The interaction between fluid and elastic solid in a fluid-filled pipe plays a key role in pipeline vibration. The fluid-structure coupling effect has a direct impact on the pipe dynamic characteristics. In this paper, using experiments and numerical analysis, a fluid-filled pipe system under the fluid-structure interaction is employed to study its dynamic characteristics, such as pipeline vibration modal, amplitude frequency response and so on. According to the coupling relationship of the three-dimensional fluid wave equations and structural dynamics equations, the 3D piping system is modeled as a fluid-solid coupling finite-element model, and the modal testing of the system is carried out considering two different cases, pipeline without water and with water. Comparing the numerical results with test data, the fluid-solid coupling dynamic model is validated and the effects of fluid on the pipeline modal are analyzed. The influence and mechanism of coupling characteristics on amplitude-frequency responses of the pipe system are investigated at different excited frequencies. It is found that the effects of water medium reduce remarkably pipe natural frequencies, but the effects of fluid on pipe amplitude frequency responses are variable at different frequency.