Numerical and experimental researches on guided waves-based probability damage imaging method of composite laminates

The damage location and recognition problems of composite laminates are studied numerically and experimentally by Lamb waves technique. The damage presence probability method (DPPM) is developed based on the arrival time difference method (ATDM) and Wigner-Ville distribution (WVD). The hole damage on the composite laminates can be identified by the proposed imaging algorithm. The damage reflection signal of Lamb waves is analysed by WVD, with their arrival times extracted. The global time difference relationship is established, and the results of the global probability-based diagnostic imaging can be obtained by matching the actual time difference with the global time difference. The damage area is centred on the maximum value of damage probability and surrounded by a certain confidence interval. The proposed method is verified by comparing the numerical examples with experiment. The results of simulation show a high degree of concurrence with those of experiment. The selection of excitation centre frequencies and PZT transducers layout are optimised. Different shape damages and multiple damages in the composite laminates can be identified by the proposed method. Multiple damage locations are identifiable regardless of PZT transducer layout, but damage shape depends on the layout’s relative position. Damage outside the layout may have unidentifiable boundaries.