Issue34

M. Scafidi et alii, Frattura ed Integrità Strutturale, 34 (2015) 622-629; DOI: 10.3221/IGF-ESIS.34.68 623 components of complex geometry [10-13]. To facilitate the automation of the analysis, TOFD B-scan maps with selected wave types can be obtained by optimizing the layout of the laser system. The aim of this work is the automatic definition of size, shape and position of the defects in plates of known thickness. A virtual image of the section of the analyzed component is created by an algorithm that locates the areas with defects. A second algorithm allows determining also the boundary shape of the defect. U LTRASONIC SYSTEM AND LASER LAYOUT DESCRIPTION he laser system used in this work, shown in Fig. 1, consists of: - an IR Nd:YAG pulsed laser for the ultrasonic wave generation; - a CW laser interferometer as receiver system for the out-of-plane displacements measurement; - a motorized linear micro-slide; - a system for data acquisition and processing. Figure 1 : Laser system: (A) IR Nd:YAG pulsed laser for ultrasonic wave generation; (B) CW laser interferometer receiver; (C) motorized linear micro-slide; (D) sample. In the application here considered, the wave generation and detection are made on the same side of a panel of thickness T at a defined distance D (see Fig. 2). The laser source generates longitudinal, shear and surface waves in the ablation regime whose angular dependence is reported in ref. [4]. Figure 2 : Cross-section of a plate with indication of laser source, laser receiver and wave paths. T