Damage identification in welded structures using symmetric excitation of Lamb waves

Damage monitoring systems based on Lamb wave health monitoring technology have attracted considerable attention for scientific research and industrial applications. In this article, two types of single-mode Lamb waves are obtained using symmetric and anti-symmetric methods, respectively, to determine a crack identification signal. A numerical simulation of a welded steel plate model was conducted using the ABAQUS/EXPLICIT module, which is a dynamic solver. The propagation process and the corresponding effect of the Lamb waves over the complete and damaged models are simulated. According to the propagation characteristics and with the assistance of the ellipse localization method with MATLAB, the location of crack damage is simulated by the amplitude addition method and the crack damage location is determined. The results show that the simulation results are in good agreement with the actual crack damage. Furthermore, the received signals are compared and analyzed from an energy perspective. Two types of single-mode Lamb wave monitoring methods are also compared. In addition, it is demonstrated that a symmetric excitation can simplify the received waves and recognize crack damage in plates in welded steel structures from an experimental perspective of this work.