利用多尺度方法研究包含微裂纹金属材料在加载条件下的动力学行为.多尺度方法结合了分子动力学和自适应有限元方法.分子动力学方法用于局部缺陷区域,有限元方法用于整个模型区域,两种方法之间用桥尺度函数进行连接.计算结果既包括了系统宏观的物理信息(应变场、应力场等),也包括了微观原子的物理信息(原子位置坐标等).模拟结果发现,在裂尖的传播过程中将发射位错,同时,拉伸应力和应变将主要集中在裂纹的两端.正是由于应力的集中导致了裂纹的进一步加速传播,最后形成宏观的断裂效应.
The multi-scale numerical simulation method was used to simulate the dynamic behaviors of crack in metal Al under tensile loading. This technique involves the molecular dynamics method used in local defect domain and finite element method used in whole field of model. A bridge-scale function is used to combine the methods of two above. Based on the data analysis of the calculated strain field, stress field and atom position, it is revealed that dislocations are emitted from the tip of crack, and the stress converged on crack accelerates the propagation of crack,which results in the macro failure of material finally.