基于压电传感器的铝合金孔结构损伤识别方法

A method for corrosion damage and fatigue crack caused by corrosion at the central hole of aluminum alloy based on Lamb wave was proposed to identify damage types. The pitch-catch piezoelectric sensor layout and ScanGenie II integrated structural health monitoring scanning system were applied. The frequency of Lamb wave was 50-200 kHz, the sampling frequency was 12×10⁶s^-1 and 24×10⁶s^-1, respectively. The finally S₀ and A₀ mode of Lamb wave with different damage types were extracted for analysis. The results show that Lamb wave S₀ mode is sensitive to fatigue crack propagation damage caused by corrosion, and the amplitude of S₀ mode decreases gradually with crack propagation. Lamb wave A₀ mode is sensitive to corrosion damage. With the increase of corrosion area, the amplitude of A₀ mode increases gradually, and with the increase of corrosion depth, the amplitude of A₀ mode decreases gradually. Extracting specific Lamb wave mode and calculating the damage index, and establishing mathematical model can predict the damage size.