A correlation filtering-based matching pursuit (CF-MP) for damage identification using Lamb waves

Time of flight (ToF) plays a key role in positioning structural damage, but the exact determination of ToF in complicated Lamb wave signals is somewhat challenging. A signal processing approach, taking advantage of correlation filtering-based matching pursuit (CF-MP), was developed. In this approach, correlation among wave signals captured from the same structure under different damage statuses was calibrated, which served as an indicator for the occurrence and severity of structural damage. The ToF of a damage-scattered Lamb wave was pinpointed with high precision. With it, the approach was then applied to Lamb wave signals acquired from delaminated carbon-fibre/epoxy (CF/EP) composite beams, and the location and size of the delamination were exactly predicted. Experimental validation indicated that such an approach is able to filter boundary-reflected signal components involved in a complex wave signal, making the wave-based damage identification technique practical for small structures.