Guided Wave and Probability Based Diagnostic Imaging for Detection of Multiple Welding Damages in Welded Tubular Steel Structures

摘要

Propagation of guided waves (GWs) in a welded tubular steel structure (WTSS)with rectangular cross-section is investigated using experimental analysis and finiteelement method (FEM) simulation with the purpose of identifying multiple weldingdamages on it. A sensor network made up of sixteen piezoelectric wafers isestablished on the WTSS, generating and collecting GWs. With the aid of a seriesof signal processing, a time-domain feature, termed ‘time of maximal difference'(ToMD) is extracted from each captured GW signal. Base on the ToMDs, a novelconcept ‘damage presence probability' (DPP) is consequently defined. Finally, aprobability-based damage imaging approach and a two-level image fusion schemeare adopted to predict presence and location of two different damages in weldingzones of the WTSS as validation. Both simulation and experimental resultsdemonstrate the effectiveness of the developed approach for identifying multipledamages in similar structures.