Voxel-scale digital volume correlation ( v-dvc )

To analyze the displacement field in volumes imaged by X-ray tomography at several deformation states, a new approach is proposed whereby the displacement is measured down to the voxel scale and determined from a mechanically regularized system using the equilibrium gap method and additional boundary regularizations. It is then possible to compute a displacement vector for each voxel, inducing lower residuals (in terms of experimental data). As representative reconstructed volumes lead to large numbers of degrees of freedom, a dedicated GPU computational strategy has been developed and implemented. A set of volumes of size 100 × 170 × 256 voxels (i.e., more than 13 million kinematic unknowns), which corresponds to a part of a sample made of nodular graphite cast iron and tested in tension, is analyzed.