基于分子动力学的α-SiO2晶体力学性能

采用分子动力学方法, 结合Tersoff势函数, 模拟α-SiO₂晶体在应变加载下的力学性能, 并考察温度对α-SiO₂力学性能的影响. 结果表明: α-SiO₂在常温加载过程中经历了弹性变形、 塑性变形及断裂变形3个阶段, 获得的屈服强度为22.6 GPa, 断裂强度为36 GPa； 在塑性变形阶段观察到α-SiO₂从晶相向非晶转化的相变过程; 随着温度的升高, α-SiO₂的屈服强度和弹性模量逐渐降低； 温度越高断裂应力和断裂应变越低, α-SiO₂晶体在高温单轴加载下易出现断裂.

Mechanical Properties of α-SiO2 Crystal Based on Molecular Dynamics

The mechanical properties of the α-SiO₂ crystalunder the loading of strain were simulated by using molecular dynamics method with Teroff potential function， and the effects of temperature on the mechanical properties of α-SiO₂ were studied. The results show that the α-SiO₂ crystal undergoes three stages of elastic deformation, plastic deformation and fracture deformation inthe process of uniaxial loading at room temperature, in which the yield strength is 22.6 GPa, the fract ure strength is 36 GPa. The transformation of α-SiO₂from crystal phaseto amorphous phase is observed during plastic deformation. The yield strength and elastic modulus of α-SiO₂ decrease gradually with the increase of temp erature, and the higher temperature, the lower fracture stress and fracture strain, the α-SiO₂ crystal is easy to fracture under high temperature uniaxial loading.