基于智能压电材料的Lamb波法结构损伤识别研究

发布时间：2018-12-14 20:47

【摘要】：随着科学技术的高速发展,大型工程结构和机械结构的应用越来越广泛,复杂的工作环境以及连续高强度的生产过程对结构的稳定性和安全性提出了更高的要求。结构健康监测及损伤识别技术对于及时检测与发现结构的损伤并预判损伤的发展,避免发生安全事故造成财产损失及人员伤亡具有重要意义。本文进行了基于智能压电材料的Lamb波法结构损伤识别研究,首先研究了Lamb波的频散特性。对Lamb波的Rayleigh-Lamb方程进行了变形推导,并使用MATLAB对Lamb波的Rayleigh-Lamb方程进行数值仿真,绘制了频散曲线;确定A0模态和S0模态的群速度与频厚积之间的对应关系,作为Lamb波进行结构损伤识别的依据。然后,使用ANSYS对智能压电材料PZT的进行了振动模态仿真分析,确定了用于激发Lamb波的激励信号的最佳中心频率,并结合MATLAB和ANSYS的仿真结果对激励信号的相关参数进行选择。最后,使用PZT作为Lamb波激励器与接收器,进行了Lamb波法结构损伤识别实验,实现了基于智能压电材料的Lamb波法结构损伤定位。实验中,设置了实验平台,采用Lab VIEW设计了实验的控制系统,实现了Lamb波激发和数据采集的同步触发。在实验研究中,分别对健康状态的铝板、人工开槽损伤状态铝板和人工钻孔损伤状态铝板进行了损伤识别研究。对采集的实验数据,使用小波分析等信号处理技术,找出了Lamb波信号传播的时间,计算出Lamb波的传播距离用以定位损伤的位置,并对不同类型的损伤和不同程度的损伤的波形信息进行了比较分析。本次实验研究实现了基于智能压电材料的Lamb波法结构损伤定位,并对结构损伤类型和损伤程度进行了简要分析,为进一步深入研究做准备。
[Abstract]:With the rapid development of science and technology, the application of large engineering structures and mechanical structures is becoming more and more extensive. The complex working environment and continuous and high strength production process put forward higher requirements for the stability and safety of the structures. The technology of structural health monitoring and damage identification is of great significance to detect and detect the damage of the structure and predict the development of the damage in time, and to avoid the property loss and casualties caused by the safety accident. In this paper, the damage identification of structures using Lamb wave method based on intelligent piezoelectric materials is studied. Firstly, the dispersion characteristics of Lamb waves are studied. The Rayleigh-Lamb equation of Lamb wave is deformed and the dispersion curve is drawn by using MATLAB to simulate the Rayleigh-Lamb equation of Lamb wave. The corresponding relation between group velocity and frequency thickness product of A0 mode and S0 mode is determined, which can be used as the basis for structural damage identification by Lamb wave. Then, the vibration mode simulation analysis of intelligent piezoelectric material PZT is carried out by using ANSYS, and the optimum center frequency of excitation signal for Lamb wave is determined, and the related parameters of excitation signal are selected by combining the simulation results of MATLAB and ANSYS. Finally, using PZT as the Lamb wave exciter and receiver, the structure damage identification experiment of Lamb wave method is carried out, and the damage location of Lamb wave structure based on intelligent piezoelectric material is realized. In the experiment, the experiment platform is set up, and the control system of the experiment is designed by using Lab VIEW. The synchronous trigger of Lamb wave excitation and data acquisition is realized. In the experimental study, the damage identification of the healthy aluminum plate, the artificial slotted damaged aluminum plate and the artificial borehole damaged aluminum plate were studied respectively. For the collected experimental data, wavelet analysis and other signal processing techniques are used to find out the time of Lamb wave signal propagation, and calculate the propagation distance of Lamb wave to locate the location of damage. The waveform information of different types of damage and different degrees of damage are compared and analyzed. In this experiment, the Lamb wave method based on intelligent piezoelectric materials is used to locate the damage of structures, and the damage types and damage degree of the structures are analyzed briefly, so as to prepare for further research.
【学位授予单位】：武汉工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB381;TB302

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