Among the several NDE and SHM techniques, ultrasonic guided waves are very suitable for the inspection ofwide structures and complex geometries. Their behavior and interaction with geometrical or potentialdefective discontinuities needs to be understood to assist the experimental set-up of NDE tests and tointerpret the collected data for quantitative damage detection and structural characterization. The Global-Local method is utilized here to investigate the guided-wave scattering in presence of very complexgeometries, involving multi-layered materials and various types of defects. The standard Finite Element (FE)approach discretizes the region with discontinuities, while the Semi-Analytical Finite Element (SAFE) methoddiscretizes the cross-section only of the waveguide geometry and propagates the solution along the wavepropagation direction, analytically through eigenvector decomposition. The two problems are coupled at theinteracting boundaries in terms of tractions and displacements, to guarantee energy conservation. Thescattering coefficients due to an incident wave mode are calculated by least square method and will be used interms of reflected and transmitted energy and cross-sectional Poynting vectors to understand frequencymodesensitivity to defects. Results will be shown for the skin-to-stringer assembly of composite aircraftstructures that are affected by various types of impact damage that are relevant to aircraft safety.
|Titolo della pubblicazione ospite||Book of Abstracts|
|Numero di pagine||1|
|Stato di pubblicazione||Published - 2019|