基于压电传感器的铝合金孔结构损伤识别方法

Damage identification method of Aluminum alloy pore structure based on piezoelectric sensor

针对铝合金含孔结构腐蚀损伤监测,提出一种基于Lamb波的腐蚀损伤识别方法。采用一发一收形式的压电传感器布局以及ScanGenie-II集成结构健康监测扫描系统。激励中心频率为50~200 kHz的Lamb波信号,采样频率分别为12×10^(6)s^(-1)和24×10^(6)s^(-1),并提取Lamb波在不同类型损伤情况下的S_(0)和A_(0)模式波包进行分析。研究结果表明:Lamb波S_(0)模态直达波对腐蚀所致疲劳裂纹扩展损伤敏感,随裂纹扩展,S_(0)模态直达波幅值逐渐降低;Lamb波A_(0)模态直达波对腐蚀损伤敏感,随腐蚀面积增大,A_(0)模式直达波幅值逐渐增加;随腐蚀深度增加,A_(0)模式直达波幅值逐渐降低。提取Lamb波特定模式波包的特征参数,并计算损伤因子,建立损伤定量模型可预测损伤尺寸。

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 12×10^(6)s^(-1)and 24×10^(6)s^(-1),respectively.The finally S_(0)and A_(0)mode of Lamb wave with different damage types were extracted for analysis.The results show that Lamb wave S_(0)mode is sensitive to fatigue crack propagation damage caused by corrosion,and the amplitude of S_(0)mode decreases gradually with crack propagation.Lamb wave A_(0)mode is sensitive to corrosion damage.With the increase of corrosion area,the amplitude of A_(0)mode increases gradually,and with the increase of corrosion depth,the amplitude of A_(0)mode decreases gradually.Extracting specific Lamb wave mode and calculating the damage index,and establishing mathematical model can predict the damage size.