Model-driven digital volume correlation: A step forward in experimental analyses of metamaterial deformations

In experimental studies involving large deformations, directing correlation algorithms to accurately capture deformed configurations may be very challenging. This task becomes particularly pronounced in metamaterials with periodic mesostructures, where correlation codes often converge to local minima due to repetitive geometric features, failing to measure the true deformed geometry. Conventional initialization methods frequently prove inadequate for metamaterials with highly complex and heterogeneous meso-architectures. A notable example includes pantographic blocks, where interconnected beam networks undergo distinct deformation patterns across different families of beams and hinges in separate regions. This paper demonstrates how a model-driven methodology integrating mechanical theory with digital volume correlation successfully solves these challenges, enabling for precise measurements of deformed shapes even under extreme displacement conditions in materials with intricate periodic mesostructures.