Quantitative identification of multiple damage in laminated composite beams using A0 Lamb mode

A Time-of-Flight (ToF)-based interrogation with a single PZT actuator-sensor pair in the pulse-echo configuration for locating and quantifying dual damage in woven laminated beams was investigated through experiments. By applying the Hilbert transform, the ToF and the reflection coefficient are extracted from each damage-induced energy component as damage-sensitive features for identifying the location and severity of damage. The resolution and limitation of this ToF-based interrogation with a single PZT actuator-sensor pair in the pulse-echo configuration for identification of multiple damage are discussed. The results demonstrated that the damage identification algorithm based on the comparison of energy spectra of Lamb wave signals captured in different states has the capability of identifying dual damage in beam-like composite structures.