On the validation of homogenized modeling for bi-pantographic metamaterials via digital image correlation

The derivation by variational asymptotic homogenization of a 2D-continuum model describing large elastic planar deformations of a discrete bi-pantographic structure is presented. A rectangular bi-pantographic specimen was additively manufactured and subjected to a bias extension test for macroscopic strains up to ca. 40%. The deformations of the bi-pantographic sample were measured via FE-based digital image correlation. Measured boundary conditions then drove the numerical model of the experiment. The gray level residuals were utilized to independently probe the kinematic hypotheses of DIC and FE simulations against the full video of the experiment for validation purposes.