In-situ monitoring of crack propagation in cellular polymeric materials: Digital volume correlation and morphometric analysis

This study investigates the influence of cellular architecture on 3D crack propagation in rigid epoxy-based foams. Using a custom-designed in situ mechanical testing device compatible with laboratory X-ray micro-computed tomography, stable crack growth was monitored under quasi-static mode I loading. Digital Volume Correlation with mechanical regularization was employed to overcome image quality constraints. We demonstrate that correlation residuals provide a robust metric for 3D crack segmentation, achieving spatial precision comparable to the voxel size (15 μ m). A comprehensive morphometric analysis was performed to compare the characteristics of cells intersected by the crack with the bulk population. These results reveal that crack path selection is primarily driven by cell volume, with cracks preferentially propagating through larger pores. Cell anisotropy was identified as a secondary governing factor, whereas cell orientation and sphericity showed no statistically significant influence. This work provides a validated framework for quantifying structure–property relationships in heterogeneous cellular materials under fracture.