*Article* **Imaging of Increasing Damage in Steel Plates Using Lamb Waves and Ultrasound Computed Tomography**

**Monika Zieli ´nska 1,\* and Magdalena Rucka <sup>2</sup>**


**Abstract:** This paper concerns the inspection of steel plates, with particular emphasis on the assessment of increasing damage. Non-destructive tests were performed on four plates, one of which was undamaged, while the remaining three had defects in the form of circular holes with diameters of 2, 5 and 10 cm. Guided Lamb waves were used in the research, and the image reconstruction was performed using ultrasound computed tomography. The damage size was estimated by tracking the real course of rays and densifying the pixel grid into which the object was divided. The results showed the great potential of ultrasound tomography in detecting defects in steel elements, together with the possibility of estimating damage size.

**Keywords:** non-destructive testing; steel plates; ultrasonic tomography; damage detection
