【作者】 张圣金；

【导师】 段忠东；

【作者基本信息】 哈尔滨工业大学 ， 结构工程， 2008， 硕士

【摘要】 结构健康监测是设备状态监测和故障诊断的基础,智能材料与结构的应用是进行结构健康监测的重点。PZT(锆钛酸铅压电陶瓷)能广泛应用于智能材料结构中。PZT能与基体材料很好结合,具有正压电效应和逆压电效应,在智能材料结构中既能用作传感元件又能用作驱动元件。PZT还具有较好的机电耦合系数、压电常数、机械品质因数、居里温度和稳定性等。本文充分发挥PZT既可作为传感器又可作为驱动器的优势,进行铝板损伤检测的试验研究。主要研究内容包括:首先,采用数值方法对Lamb波进行建模,并对Lamb波激励进行优化。其次,基于压电基本理论,介绍PZT电压感知机理和阻抗感知机理,以及PZT压电陶瓷各种性能参数对PZT材料特性的影响;研究PZT驱动、感知元件的制作与粘贴工艺,建立结构主动健康监测试验平台。第三,通过试验,研究PZT用于铝板结构裂缝损伤的检测。验证Lamb波群速度频散曲线;研究基于最小二乘法的峰值损伤因子;应用波传播时间延迟和能量-时间谱的衰减,结合板的对称性,对单一裂缝损伤、单一有蜡填充裂缝损伤、多处裂缝损伤进行损伤检测进而精确定位,试验结果证实该方法是切实可行的。最后,探讨了损伤率用于判断结构健康状况的方法。更多还原

【Abstract】 Structural Health Monitoring is the base of equipment status monitoring and failure diagnosing with focus on the application of smart materials and structure in which PZT is widely used.Adhering well to the matrix, Piezoelectric ceramics have piezoelectric effect and inverse piezoelectric effect and can function as both sensor component and driving component in the smart materials and structure. There are also advantages of PZT in electromechanical coupling coefficient, piezoelectric constant, mechanical quality factor, curie temperature and stability etc.Giving full play to the advantages of PZT used as both sensor component and driving component, this thesis carries out research on the identification of the aluminum plate damages, including the followings: Firstly, Lamb waves travelling in the aluminum plate is modeled through numerical methods, and the optimization of the Lamb waves incentive is done. Secondly, based on the piezoelectric theory, this thesis introduces the PZT voltage sensing mechanism, the impedance sensing mechanism and the impacts which various performance parameters of PZT exert on the characteristics of PZT material. The experiment platform is also founded for the active structural health monitoring and reseach is done on the making and sticking of PZT sensors and actuators.Thirdly, PZT for the identification of the aluminum plate crack is studied through the experiment. The dispersion curve of the group velocity of Lamb waves is drawn, which agrees largely with the theoretical curve. The peak damage factors are studied based on the least-squares method. With the application of the delay time of wave propagation and the attenuation of the energy-time spectrum, the identification and precise positioning of damages are conducted on a single crack damage, a single wax-filled crack and multiple cracks employing the symmetry of the square board. This experiment method has been proved to be feasible. Finally, this thesis explores the damage index on the judgement of the health situation of the structure.更多还原