Multiscale FE-based DIC for improved full-field measurements and identification
Résumé
Over the three last decades, full-field measurement techniques have become increasingly popular in the community of experimental mechanics. Among these techniques, Digital Image Correlation (DIC) is widely used thanks to its (apparent) simplicity, although it suffers from a lack of information about its actual metrological performances. The measured displacement fields can subsequently be used to identify mechanical constitutive parameters. In this work, it is proposed to use successively a Finite Element-based DIC method and a Finite Element Model Updating (FEMU) procedure. In practice, DIC uncertainties are closely related to the spatial resolution. As a consequence, an inappropriate mesh can lead to large uncertainties, which can become detrimental for the identification procedure. In this work, images taken at different scales (and therefore with different resolutions) are exploited in order to overcome the well-known spatial resolution / uncertainty compromise. An ad-hoc FEMU strategy is proposed to take advantage of the multiscale measurements.