Molecular dynamics study on the anisotropy of α-quartz fracture properties

The anisotropy of micro fracture properties of α-quartz was systematically studied under tensile loading based on molecular dynamics simulations. Tensile loads were applied to α-quartz models with various defects to investigate fracture phenomena, energy evolution, and trends in mechanical properties along the x ([2 1 0]), y ([0 1 0]), and z ([0 0 1]) directions. The results show that loading direction significantly affects fracture mode, mechanical properties, and energy distribution: the x direction exhibits greater elastic energy storage capacity, the y direction has the highest surface energy consumption, and the z direction shows superior fracture strength and structural stability. However, the anisotropy of the fracture process decreases as defect size increases. Prefabricated defects markedly reduce the material’s fracture strength and energy demand. The maximum reductions in fracture strength are 44.87 %, 41.57 %, and 23.12 % for the x ,y, and z directions, respectively, while input energy reductions are 62.98 %, 62.03 %, and 46.00 %. This study systematically elucidates how prefabricated defects and loading directions influence fracture mechanisms and mechanical properties at the atomic scale, highlighting the critical role of anisotropy in energy distribution during fracture. The findings offer theoretical support for energy optimization in mineral crushing and dissociation while providing new insights into the mechanical properties of brittle materials.