Abstract:Structure health monitoring (SHM) for complex structures is highly practical in engineering field. Channel-like aluminium alloy structures were evaluated in terms of both finite element method (FEM)- and experiment-based Lamb wave analysis for the purpose of damage detection. Three-dimensional FEM models were established to simulate the propagation behavior of Lamb wave in the structures. In experiments, piezoelectric lead zirconate titanate (PZT) wafers were employed to generate Lamb waves propagating in the structures as actuators and collect Lamb wave signals as sensors. Taking advantage of continuous wavelet transform (CWT) and Hilbert transform (HT), time domain feature of the collected Lamb wave signals, time-of-flight (ToF) of the crack scattered wave component was extracted. Quantitative relationship between crack location and the ToFs was established consequently.