【作者】 王达；

【导师】 赵树山；

【作者基本信息】 哈尔滨工业大学 ， 固体力学， 2008， 硕士

【摘要】 本文的主要工作就是研究通过宏纤维复合材料(Macro-Fiber-Composite)对管道结构进行主动控制的可能性以及实现方法。通过有限元仿真得到管道结构的振动模态数据。在此基础上,利用宏纤维复合材料,通过闭环控制系统实现了管道在20Hz低频段的控制作用。首先,研究了压电效应机理以及压电材料的特性。给出了宏纤维复合材料的压电作动机理,证明了其在电压驱动下的位移特性适合被应用在本实验的振动控制方面。然后,利用ANSYS软件完成了管道振动模型的建立、模态分析等工作。由于本实验所采用的MFC只对横向振动进行控制,所以须排除其非横向振动模态的振型。得到了其前十阶横向振型,对下一步的振动控制具有相当大的指导作用。最后,设计了主动控制结构模型的总体设计。在此基础上具体实现了振动信号的数字滤波、数值校正工作。通过对不同信号放大比的设定,试验证明,最好的控制效果发生在宏纤维复合材料驱动电压满额工作的情况下。该现象同时也证明该压电材料的驱动力还有待进一步提高。振动幅值减小量随着驱动信号放大比的减小成近似比例的减小,证明了该驱动器工作能力比较稳定。当对被控制管道长度进行调整时,作动效率降低很快,甚至会发生失稳现象。该现象证明作动器与传感器固定的位置对作动效果影响很大,需要在未来的研究中进一步完善。更多还原

【Abstract】 In this paper, the possibility of the vibration control by MFC (Macro Fiber Composite) on the pipe structure and the method of active vibration control is realized in some degree. Through the finite-element method, the mode data of pipe structure is obtained. And then, with the help of MFC, the closed-loop control method is realized in the low frequency of 20Hz.Firstly, the piezoelectric theory and the character of piezoelectric material are studied. The voltage-strain relationship figure is shown which proves the character of MFC is fit for active vibration control to pipe structure in a certain degree.Secondly, the pipe structure is built by ANSYS program and the mode analysis is finished. Ignoring the modes which are not in the cross direction, the first 10 modes are obtained which are the main guide for the placement of MFC and sensing device.Finally, the main design of active vibration control structure is designed. With the help of the design, the work of digital filtering, data correction are realized. From setting different proportion of controlling program, it could be seen that the best controlling condition happens when the MFC is working in full scope. The result also shows that the driving ability of MFC is still limited. The reducing rate of vibration is in proportion relationship with the driving Vpp data, which proves the stability of MFC. When changing the length of the pipe, the efficiency of vibration control is reducing quickly, even loose stability, which means the position of MFC and sensing device affects the controlling efficiency affectively. And the position theory is needed to be studied in the future research.更多还原