压电晶片传感器监测金属薄板的腐蚀

激励压电晶片传感器产生Lamb波并用于监测金属板材的腐蚀,由信号的相关系数表征腐蚀对在板中Lamb波传播特性的影响。实验结果表明在Lamb波模态中A₀模式受腐蚀影响大,适合用于监测金属的腐蚀。Lamb波通过腐蚀区域后由于频散以及信号幅度和相位的变化对采集的损伤信号与健康状态信号的相关系数有影响。在腐蚀区域直径一定的情况下,对应的相关系数并不随腐蚀深度的增加而单调递减;在腐蚀深度一定时,相关系数随腐蚀区域直径增加而单调递减。

Corrosion damage detection of a metal sheet with piezoelectric wafer active sensors

Lamb waves excited by piezoelectric wafer active sensors are applied to detect corrosion damage of a metal sheet. The influences of the Lamb waves are analyzed by signal correlation coefficient between the signals of health state and corrosion state. The results indicate that, A0 mode of the Lamb wave is affected by the corrosion degradation. The A0 Lamb wave is good for corrosion detection. Furthermore, the correlation coefficients are monotonic decreasing with the increasing corrosion area when corrosion depth is fixed. However, when the corrosion depth is gradually deep from surface to bottom, the coefficients decrease firstly and then increase