Analysis of damage in hybrid composites subjected to ballistic impacts : an integrated non-destructive approach

In this chapter infrared (IR) vision has been used as non-destructive testing (NDT) method for the detection of damage occurred in hybrid composites subjected to high velocity impacts. In particular, carbon and basalt fibers have been used in the fabrication of the laminates with an intercalated and a sandwich-like structure. Near-infrared reflectography (NIRR) and infrared thermography (IRT) techniques have shown interesting complementarities, as well as the integrated image processing by using advanced algorithms, such as Partial-Least Square Thermography (PLST) and Principal Component Thermography (PCT). The laminates have been subjected to a long square pulse in order to make possible the acquisition of both the heating and the cooling phases, while the prediction of the damage due to the impacts has been evaluated by finite element (FE) analysis. Preliminary results inherent to the numerical simulation approach are reported. Finally, the damage state has been compared with a detailed fractographic analysis of the laminates’ cross-sections, and qualitatively estimated by segmentation algorithms, thus confirming the potential of the proposed integrated approach