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用分子动力学方法对金属界面在弯曲状态下的力学行为做了模拟计算.在自行设计的两种弯曲模型中,首先比较了Ag/Ni在不形成界面、形成界面(错配比约为15%)以及Cu/Ni形成界面(错配比约为3%)时在动态弯曲过程中的势能-应变曲线,应力-应变曲线,模量-应变曲线,通过比较得出的结论是:界面的存在影响很大,失配位错影响界面的性质,并且错配比不同界面的力学性质亦不相同.同时,对计算元胞的尺寸效应做了详细的讨论,给出了用于计算机模拟中比较适宜的计算元胞的尺寸.最后,利用圆弧弯曲模型将静态平移周期性边界条件应用于动态弯曲过程中,克服了三点弯曲模型中硬边界条件的不足之处,在弹性区内得出的结论与虎克定律符合得很好.模拟计算工作所用的原子间势函数为Lennard-Jones势.
The molecular dynamics method was used to simulate the mechanical behavior of the metal interface under bending conditions. In the two curved models designed by ourselves, we first compared the dynamic behavior of Ag / Ni at dynamic interface (interface ratio of about 15%) and interface of Cu / Ni (mismatch ratio of about 3% The results of potential energy-strain curve, stress-strain curve and modulus-strain curve during bending show that the existence of interface is greatly affected, mismatch dislocation affects the properties of the interface, and the mismatch ratio of different interfaces The mechanical properties are not the same. At the same time, the effect of calculating the size of the cell is discussed in detail, and the suitable size of the calculated cell for the computer simulation is given. Finally, the arc bending model is applied to the dynamic translation of the static translational periodic boundary conditions, which overcomes the shortcomings of the hard boundary conditions in the three-point bending model. The conclusion drawn in the elastic region is consistent with Hooke’s law well. The atomic potential function used in the simulation work is Lennard-Jones potential.