Detection of a notch type defect at 0°, 45° and 90° Orientations by a Network of Interdigitated Piezopolymer Transducers for Structural Health Monitoring

In the field of SHM (Structural Health Monitoring), the timely detection of defects is essential to guarantee the integrity and robustness of the structure. In the case of structures made of aluminum panels, it is necessary to detect the presence of defects even of small size, such as sub-millimeter notches, which can initiate the propagation of cracks, compromising the integrity of the structure. Ultrasonic Guided Waves (UGWs) are commonly used for this purpose but the challenge for the applicability in SHM is to design interdigital transducers (IDT) covering large areas to minimize the transducers density. In this work we present a study of the scattered signal at different notch orientations. The outcome of this study is the assessment of the detection of longitudinal cracks that is the most critical condition.