Ultrasonic Imaging via Digital Antenna Focusing Technique Using High-Frequency Lamb Waves

Ultrasonic testing using guided waves, particularly Lamb waves, is a powerful tool for inspecting thin objects. This paper considers the implementation of ultrasonic testing with Lamb waves using digital antenna focusing technique (DFA). By using high-frequency Lamb waves generated through the use of wedges, it is possible to perform ultrasonic testing using conventional ultrasound equipment. To enhance the quality of the image restoration, a post-processing approach has been proposed, which combines the application of conventional algorithm within DFA and Phase Coherent Imaging (PCI). Experimental results demonstrate that this combined approach effectively restores images of flaws located at various depths with high signal-to-noise ratios, demonstrating the promising potential for this technique in pulse-echo ultrasonic inspection. These findings expand the range of applications for phased-array ultrasonic systems.