Data-fusion NDE for progressive damage quantification in composites

The objective of this article is to present a progressive damage quantification framework for fiber reinforced polymer composites (FRPC) that have widespread use in aerospace and wind-turbine applications. To this aim, a novel optico-acoustic nondestructive evaluation (NDE) setup is presented based on integration of Digital Image Correlation (DIC), Acoustic Emission (AE), and Infrared Thermography (IRT). DIC and IRT full-field strain and temperature maps reveal early development of structural hot spots, associated with locations where inelastic strains accumulate, damage initiates, and final fracture occurs in both tensile and fatigue experiments. Damage quantification is further related to: (i) energy dissipation, (ii) residual stiffness, (iii) average both temporal and spatial temperature variations, and (iv) AE features in time and frequency domains. The extracted NDE parameters suggest three characteristic stages of fatigue life that can be used to construct appropriate models for reliable remaining life-predictions.