Presentazioni e Articoli Tecnici

Within the field of Non Destructive Testing (NDT) of materials, nonlinear ultrasonic techniques are becoming increasingly popular, since they provide extreme sensitivity in detecting the presence of incipient damage. However, the next step forward would be to fully characterize the detected defects (e.g. by estimating their geometric parameters), allowing to make some prediction about lifetime or serviceability of the tested samples and structures. This can for instance be done by comparing the experimentally obtained nonlinear indicators with the results obtained by an effective numerical model. On the other hand, such models can also be used to assist in the further development and optimization of the existing experimental ultrasonic NDT techniques. To obtain a better understanding and analysis of the nonlinear behavior of early-stage damage features, we developed and investigated the results of a two-dimensional numerical model for elastic wave propagation in solid materials containing closed cracks.