Abstract
To visualize inaccessible internal interface debonding defects in concrete-filled steel tube (CFST) specimens, a threshold-based probability imaging algorithm using surface wave measurements from surface-mounted piezoelectric lead zirconate titanate (PZT) patches is proposed in this paper. The algorithm employs a density-based spatial clustering of applications with noise (DBSCAN) analysis and a probability imaging framework. To verify the applicability and accuracy of the proposed approach, experimental and numerical studies were conducted on rectangular CFST (RCFST) specimens with mimicked interface debonding defects. The results demonstrate that, compared with traditional probability imaging methods, the threshold-based probability imaging algorithm can more precisely localize the existence and visualize the dimensions of the mimicked interface debonding defects in the RCFST specimens even with complex internal design details such as shear studs and diaphragm. The proposed method provides an effective solution for the quantitative detection and visualization of inaccessible interface debonding defects in RCFST specimens.