Improvement of the Digital Image Correlation close to the borders of an object

Maxime Baconnais (1) , Julien Réthoré (1) , M.L.M. François (1)

1 GeM - Institut de Recherche en Génie Civil et Mécanique

The measurement error of the finite-element-based Digital Image Correlation is reduced along the borders of an object by using the precise measurement, obtained by Virtual Image Correlation (VIC). The proposed method is called Virtual and Digital Image Correlation (VDIC). The boundary, identified by the VIC with a subpixel precision, is used firstly to create an adapted mesh and secondly to create a pixel mask. Futhermore, the VDIC also uses the VIC measurement of the boundary in the deformed state as a constraint on the radial displacement field along the border. The optimal values of the parameters of the VDIC are discussed throughout a sensitivity analysis. The compared performances of the constrained and unconstrained VDIC are obtained thanks to a synthetic test of a plate with a hole in tension. Finally, the method is checked on a sample geometry which includes holes and a U-shaped notch.

Mots clés: adapted mesh; boundary displacement; digital image correlation; pixel mask; virtual image correlation

Domaines: Mécanique des solides [physics.class-ph]

Maxime Baconnais, Julien Réthoré, M.L.M. François. Improvement of the Digital Image Correlation close to the borders of an object. Strain, 2020, 56 (3), ⟨10.1111/str.12340⟩. ⟨hal-02920373⟩