This paper aims to improve the flexural stability of rotating pipes conveying fluid by introducing a smart piezoelectric feedback structure. The pipe is laminated along the radial direction, and a steady fluid flows inside the pipe. In the meantime, the pipe rotates around a vertical axis at one end. A pair of piezoelectric sensor and actuator connected with a feedback gain circuit are designed to place on the pipe in order to reduce the transverse vibration by providing dynamic stiffness. Theoretical modeling finds it a fully coupled system among the axial, in-plane and out-of-plane transverse direction due to the presence of the piezoelectric feedback structure. However, such smart structure is demonstrated to have excellent capability of enhancing the natural frequency and static and dynamic critical flow velocities of the pipe. Vibration response analysis also reveals an interesting phenomenon that under the gyroscopic effect of flowing fluid, the introduced piezoelectric design is able to attenuate the vibration of the system periodically, similar to a beat vibration. This study is expected to provide a technical way for enhancing the stability of engineering motional pipes.

中文翻译：

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通过智能压电设计提高旋转复合管道输送流体的动态稳定性


本文旨在通过引入智能压电反馈结构来提高旋转管道输送流体的弯曲稳定性。管道沿径向层压，稳定的流体在管道内流动。同时，管道的一端绕垂直轴旋转。一对与反馈增益电路相连的压电传感器和致动器被设计放置在管道上，以便通过提供动态刚度来减少横向振动。理论建模发现，由于压电反馈结构的存在，它在轴向、面内和面外横向之间是一个完全耦合的系统。然而，这种智能结构被证明具有提高管道固有频率以及静态和动态临界流速的出色能力。振动响应分析还揭示了一个有趣的现象，即在流动流体的陀螺效应下，引入的压电设计能够周期性地衰减系统的振动，类似于节拍振动。本研究有望为提高工程运动管道的稳定性提供一条技术途径。