Improved Global-Local Method for Ultrasonic Guided Wave Scattering Predictions in Composite Waveguides and Defects

As structures increase in complexity, in the use of high-performing materials and designs, their health assessment becomes increasingly challenging. Ultrasonic guided waves (UGWs) have shown to be very promising in the inspection of large (i.e. aerospace components) attenuating (i.e. composite materials) structures and have been successfully employed for damage detection in a variety of fields. The intrinsic complex nature of UGWs, due to their dispersive behavior, combined with the structural complexity of the applications, though, makes the interpretation of UGW inspections very challenging. Numerical simulations of UGW propagation become crucial to this end and have been addressed with fully numerical, semi-analytical and hybrid approaches. The capability of predicting UGW scattering can inform experimental testing in optimizing the sensitivity of UGW inspections to specific waveguides and defects, and in interpreting the acquired data for the non-destructive identification and quantification of damages. In this work, an improved computational tool for UGW scattering predictions is presented. The approach relies on the Global-Local method and leverages the efficiency of the semi-analytical finite element (SAFE) method and the parallelized implementation of the coupled solution. 2D applications of the Global-Local approach for UGW scattering predictions in composite structures over a wide range of frequencies will be presented, together with the demonstration of the improved computational performance. The computational efficiency promises feasible and reliable UGWs predictions in multi-layered complex assemblies and different damage scenarios, and enables virtual UGWs inspections and future integration in NDE testing.