High-Resolution Crack Localization Approach Based on Diffraction Wave

Abstract

The delay-and-sum imaging algorithm is a promising crack localization approach forcrack detection and monitoring of key structural regions. Most studies successfully offer a hole-likedamage position. However, cracks are more common than hole-like damages in a structure. To solvethis issue, this paper presents a crack localization approach, based on diffraction wave theory, whichis capable of imaging crack endpoints. The guided wave propagated to the crack endpoints andtransformed into a diffraction wave. A line sensor array was used to record the diffractionwaveform. Then, dispersion compensation was applied to shorten the dispersive wave packets andseparate the overlapping wave packets. Subsequently, half-wave compensation was executed toimprove the localization accuracy. Finally, the effectiveness of this high-resolution crack localizationmethod was validated by an experimental example.