(南昌航空大學 航空制造工程學院，南昌 330063)
摘 要: 采用分子動力學方法研究鋁的裂紋擴展行為。建立鋁的分子動力學模擬模型，通過嵌入原子法進行模擬，得到鋁裂紋擴展過程中的原子軌跡圖與能量演變圖。從裂紋擴展圖清楚地觀察到裂紋擴展的變化情況：裂紋尖端鈍化、子裂紋的產(chǎn)生、孔洞的生成及長大過程以及裂紋和孔洞的匯集。能量演變圖中詳細地說明了整個體系演變的過程。探討加載速率和初始裂紋長度對體系裂紋擴展行為的影響。結果表明：隨著加載速率的增大，原子運動程度加劇，體系完全被拉開的時間縮短；初始裂紋長度越長，原子運動的細節(jié)表現(xiàn)越不明顯。
關鍵字: 鋁；裂紋擴展；分子動力學模擬；能量演變；加載速率；初始裂紋長度
（School of Aeronautical Manufacturing Engineering, Nanchang Hangkong University, Nanchang 330063, China）
Abstract: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.
Key words: aluminum; crack propagation; molecular dynamics simulation; energy evolution; loading rate; initial crack length
