论文标题
通过小振幅振荡剪切变形在无定形材料中剪切带愈合
Shear band healing in amorphous materials by small-amplitude oscillatory shear deformation
论文作者
论文摘要
使用分子动力学模拟研究了小振幅周期性剪切对二元眼镜中剪切带退火的影响。首先通过大振幅周期性剪切在稳定的玻璃杯中引入剪切带，然后在数千个循环中以低于屈服应变的应变幅度下的数千个循环中重复载荷。已经发现，随着应变振幅的增加，玻璃被重新安置到更深的势能水平，而退火时的能量变化不受玻璃初始稳定性的影响。机械测试的结果表明，在前几百个循环中，剪切模量和屈服应力均向高原水平增加，并且当在接近屈服应变的应变幅度下将样品加载时，它们的幅度最大。对非植物位移的分析表明，剪切带分解为逐渐衰减的孤立簇，导致弹性范围内几乎可逆变形。这些结果可能对金属眼镜和添加剂制造的机械处理可能很有用。
The effect of small-amplitude periodic shear on annealing of a shear band in binary glasses is investigated using molecular dynamics simulations. The shear band is first introduced in stable glasses via large-amplitude periodic shear, and then amorphous samples are subjected to repeated loading during thousands of cycles at strain amplitudes below the yield strain. It was found that with increasing strain amplitude, the glasses are relocated to deeper potential energy levels, while the energy change upon annealing is not affected by the glass initial stability. The results of mechanical tests indicate that the shear modulus and yield stress both increase towards plateau levels during the first few hundred cycles, and their magnitudes are largest when samples are loaded at strain amplitudes close to the yield strain. The analysis of nonaffine displacements reveals that the shear band breaks up into isolated clusters that gradually decay over time, leading to nearly reversible deformation within the elastic range. These results might be useful for mechanical processing of metallic glasses and additive manufacturing.
