Model Benchmarking Studies of Angle-Beam Pulse-Echo Ultrasonic Inspection of Composites

Model benchmark studies are presented for angled-beam inspections of composites to validate the performance of two promising models. However, manual interpretation of the signal response can be quite complicated, even for inspection of side-drilled holes in a thin composite. The use of models is introduced in this paper to guide this complex signal interpretation task. Specifically, wave maps are used to illustrate the complexity of the oblique-angle ultrasound propagation in these layered anisotropic materials. For the two benchmark cases presented, each model provided the closest estimates of location and time of flight return signals for one case or the other, indicating neither model is clearly better for this specific case. In fact, it will be shown that the two models provide complimentary information in the case of angled-beam inspections of composites. Lastly, simulated results from both single and hidden delamination scenarios are studied, and contrasted with side-drilled hole benchmarking results, providing critical insight into optimization of the angle-beam pulse-echo inspection technique for characterizing hidden delaminations from a single side.