Active Control of the Fluid-Coupled Vibration of Thin-Walled Structures

管道、壳体等薄壁结构容易形成与流体有关的动力失稳，即颤振和发散。针对薄壁结构流激振动的主动控制问题，提出了一种主动控制方法。首先，对悬臂输液管道的动力稳定性和主动控制进行了理论研究。为了控制悬臂管道的响应，通过连接在管道上的一对筋产生的扭矩来获得主动控制力。此外，还使用了压电致动器来产生扭矩。利用Galerkin方法，结合最优调节器理论，求解了该问题。并对输液管道在不同条件下的响应进行了数值模拟。结果表明，在控制输入受限的情况下，基于腱机构和压电致动器的主动控制方法对输液管道的稳定是有效的，并通过采用直流伺服电机和压电致动器的实验验证了理论结果。在PC机上应用了最小阶状态观测器和数字最优调节器理论，并对壳体的流致振动进行了主动控制。

The thin-walled structures such as pipes and shells are easy to become the dynamic instability connected with fluid, that is flutter and divergence. To stabilize the flow-induced vibration of the thin-walled structures, an active control method was proposed in this study.At first theoretical studies on the dynamic stability and active control of cantilevered pipes conveying fluid were conducted. In order to control the response of the cantilevered pipe, an active control force was derived by the torque produced by a pair of tendons attached to the pipe. And also piezoelectric actuators was used to generate the torque. The problem was solved by means of the Galerkin method, in conjunction with the optimal regulator theory. The numerical simulation of the response of the pipe conveying fluid was also carried out for various conditions. It was found that the active control method using the tendon mechanism and the piezoelectric actuator is effective to stabilize the pipe conveying fluid, even if the control input is limited.Next, the theoretical results were confirmed by the experiment in which DC servo motors and piezoelectric actuators were used. Also the minimum order state observer and the digital optimum regulator theory were used with personal computers.Furthermore, the flow-induced vibration of shells was found to be suppressed by the active control.