Multiscale DIC Applied to Pantographic Structures

Background: Since the mechanical behavior of pantographic metamaterials depends upon the properties of their microstructure, accurate descriptions of unit cells are needed. Objective: The present effort is motivated by this requirement to characterize the detailed deformation of unit cells formed of two orthogonal sets of 3 beams. Methods: Their deformations in a bias extension test were measured via digital image correlation performed at different scales. Results: Thanks to the gray level residuals, the microscale results were found in better agreement with the experiment than mesoscale and macroscale analyses. Fine analyses around the hinges showed that relative displacements occurred between the two beam layers. Conclusions: Such experimental analyses supply full-field data to validate models (e.g., as a starting point in homogenization procedures) for describing the mechanical behavior of pantographic metamaterials.