Exploiting DIC-based full-field receptances in mapping the defect acceptance for dynamically loaded components

Defect acceptance can be seen dependable upon the mapping of effective strains, due to dynamic loading of the components as they are mounted. With proper constitutive models and loading spectra, the experiment-based mapping of the equivalent stresses can be achieved from full-field receptances. Fatigue spectral methods turn this knowledge into components’ life distributions, for the assessment of where the material reaches first the critical conditions for a failure, whereas can highlight areas of under utilization. Therefore, a risk grading mapping for potential defects can be formulated over the area of inquiry in order to discriminate among safe and dangerous locations. By following this experiment-based approach, potential defects in exercise and production might be tolerated in safer locations, under the chosen dynamic task, with great savings in costs and maintenance. Full-field dynamic testing can nowadays be achieved by means of optical measurements. Among the image-based ones, Hi-Speed DIC has proved to work in many environments, to be able to estimate full-field receptances of real components in their effective assembling and loading conditions also outside a specific laboratory. The quality achieved in the receptance maps helps in numerically deriving the strain FRFs on the sensed surface, to achieve, with known excitation, the experiment-based risk mapping of the real mounted component and defect acceptance criteria. Examples with coloured noises and a vibrating rectangular plate are highlighted in details.