Molecular dynamics simulation of edge crack propagation in single crystalline alpha quartz

Edge crack propagation of single-crystalline alpha quartz under mode I loading condition was investigated using a molecular dynamics simulation. Five different crack lengths are used to analyze the effects of crack length on each sample's crack growth behavior. The effect of crack length was studied in terms of the material's stress-strain curve, strain energy, fracture toughness, atomic analysis of crack propagation, and crack opening deformation. The results revealed that during tensile loading, the pre-cracked crystalline quartz samples are fractured in a brittle approach. The fracture stress in the pre-cracked sample (40 Å length) is dropped about 70% compared to pristine quartz. Moreover, the effect of loading velocity on the mechanical properties is investigated. According to the findings, maximum stress rises by enhancing the loading velocity, and fracture toughness improves. The fracture surface energy of the single crystalline alpha quartz is calculated, and based on the results, there is a good agreement with experimental data.