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主动Lamb波损伤监测中的差信号方法获取损伤散射信号容易受到结构和环境等外界因素的影响。针对该问题,提出了无参考信号的损伤成像定位和监测方法;研究了回波式压电阵列的布置方法,并设计采用时间反转窗函数,清除Lamb波监测信号中的直接传播信息和边界反射信号,以截取出内部散射信号;通过控制压电阵列布局、设置窗函数等技术条件,基于时间反转理论中对波源的自适应聚焦原理,直接利用当前状态下的传感信号实现对结构损伤的实时成像、定位与评估,不再需要健康信号作为参考。在玻璃纤维复合材料板上的实验结果表明,该方法能较为准确地实时监测出损伤的位置、范围等特征。
Differential Signal Detection in Active Lamb Wave Damage Detection Damage acquisition scattering signals are easily affected by external factors such as structure and environment. In order to solve this problem, a method of location-based damage imaging and monitoring without reference signal is proposed. The layout of echo-type piezoelectric array is studied and time-reversed window function is designed to remove the direct propagation information and boundary in the Lamb wave monitoring signal Reflected signal to intercept the internal scattering signal; by controlling the piezoelectric array layout, setting the window function and other technical conditions, based on the time-reversal theory of the adaptive focusing principle of the wave source, the direct use of the current state of the sensor signal to achieve the structure Real-time imaging, localization and assessment of lesions no longer require a healthy signal for reference. The experimental results on the glass fiber composite board show that the method can accurately and accurately monitor the location, range and other characteristics of the damage in real time.