中文摘要：

采用分子动力学方法研究铝的裂纹扩展行为。建立铝的分子动力学模拟模型，通过嵌入原子法进行模拟，得到铝裂纹扩展过程中的原子轨迹图与能量演变图。从裂纹扩展图清楚地观察到裂纹扩展的变化情况：裂纹尖端钝化、子裂纹的产生、孔洞的生成及长大过程以及裂纹和孔洞的汇集。能量演变图中详细地说明了整个体系演变的过程。探讨加载速率和初始裂纹长度对体系裂纹扩展行为的影响。结果表明：随着加载速率的增大，原子运动程度加剧，体系完全被拉开的时间缩短；初始裂纹长度越长，原子运动的细节表现越不明显。

英文摘要：

The crack propagation behavior of aluminum was studied by molecular dynamics method. The molecular dynamics simulation model of aluminum was set up, and the energy evolution map and atomic trajectory figure of aluminum crack propagation process were obtained according to the modified embedded atom method. By plotting the crack propagation graph, the change of crack propagation is observed clearly, such as the crack tip blunted, the generation of sub-crack, the formation and growth process of the void, and the collection of crack and void. The whole evolution process of the system was described in detail from energy evolution map. The effects of loading rate and initial crack length on the crack propagation behavior of the system were discussed. The results show that the degree of atomic motion is intensified and the time of system completely open is shortened with increasing the loading rate. The longer the initial crack length is, the more unobvious the details of the atomic motion are.