Screening and Tomographic Reconstruction of Defects by Structural Guided Ultrasonic Waves
| Detecting and quantifying damages in large structures is of growing interest in various industries. Conventional ultrasonic methods are tedious and expensive, especially for inaccessible areas. Ultrasonic structural guided wave offers an attractive alternative for the rapid inspection of defects from a remote position in a large structure. In this talk, two interesting applications of ultrasonic guide waves will be discussed: defect screening in structural features such as weld, stiffeners and bends, as well as defect characterization using guided wave tomographic approach. A numerical forward model is used to predict the scattering of guided wave through defects, and an iterative inverse model is developed to reconstruct the defect profile. The imaging algorithm allows higher order diffraction and scattering to be considered in its numerical solver, thus can provide accurate inversion results. Despite two guided wave applications, recent progress in the research of acoustic metamaterial and laser ultrasound will also be shared in the talk.