Mechanical and failure behavior of the viñales (L6) ordinary chondrite: linking microstructure to axial splitting fractures

The mechanical behavior and fracture evolution of the Viñales meteorite were investigated through combined microstructural characterization and quasi-static compression experiments. Elemental mapping and electron imaging reveal a material dominated by a heterogeneous distribution of silicate minerals, with embedded Fe–Ni metal and troilite grains, which, as a whole, is penetrated by pervasive shock-melt veins. Compression tests with digital image correlation show brittle stress–strain responses and highly localized deformation that evolve into complex fracture networks, producing both single and multiple axial splits. X-ray computed tomography shows that cracks preferentially propagate through the brittle phases, i.e., troilite and silicates, whereas the ductile Fe–Ni metal grains deflect or arrest their growth. These results highlight the strong influence of microstructural heterogeneity on fragmentation processes in meteorites. The findings provide new insights into fracture mechanisms in stony astromaterials, with implications for asteroid disruption, regolith formation, and predictive modeling of failure in meteoritic materials.