CAJ | 학술논문

采用嵌入原子势模型和分子动力学方法,模拟研究了三角波加载下金属铝动态破坏的微观过程和动力学性质.根据原子中心对称参数变化给出了样品微结构演化过程,解读了熔化前后破坏过程的形态差异;基于Virial定理统计了样品中压力和温度等力学量波形,分析了熔化前后材料的强度变化.通过不同碰撞速度的模拟,讨论了破碎区内物质形态和密度分布的变化,给出了材料破坏深度的变化规律.研究还发现,熔化后材料的动态拉伸强度已显著降低,而此时由声学近似推算的材料拉伸强度已明显高于内部应力直接计算结果.
채용감입원자세모형화분자동역학방법,모의연구료삼각파가재하금속려동태파배적미관과정화동역학성질.근거원자중심대칭삼수변화급출료양품미결구연화과정,해독료용화전후파배과정적형태차이;기우Virial정리통계료양품중압력화온도등역학량파형,분석료용화전후재료적강도변화.통과불동팽당속도적모의,토론료파쇄구내물질형태화밀도분포적변화,급출료재료파배심도적변화규률.연구환발현,용화후재료적동태랍신강도이현저강저,이차시유성학근사추산적재료랍신강도이명현고우내부응력직접계산결과.
Employing an embedded-atom-method potential and molecular dynamics simulations, we have simulated the microscopic process and dynamical properties of the dynamic failure of metal Al specimens under triangular wave loading. The microstructure evolution of the sample is analyzed using the central symmetry parameter, while the difference of morphology between non molten and molten states is also explained. The pressure profiles were calculated based on the virial theorem, and the results show that the tensile strength of the material is decreased considerably in its molten state. Using the simulation results for different impact velocities, we discuss the variation of morphology and density distribution, from which the change of damage depth in the process from non molten to molten states is obtained. Our simulations also suggest that: the tensile strength of material derived from acoustic approximation is distinctively higher than the peak of internal stress from virial theorem for the melted state.