论文标题
循环载荷期间交替的剪切方向有助于无定形材料的产量
Alternating shear orientation during cyclic loading facilitates yielding in amorphous materials
论文作者
论文摘要
使用分子动力学模拟研究了循环载荷的交替剪切方向和应变幅度对无定形固体屈服的影响。模型玻璃通过二元混合物表示，该二进制混合物迅速冷却了玻璃过渡温度，然后进行振荡性剪切变形。结果表明，在临界值高于临界值的应变幅度下的周期性负载首先通过在许多瞬时周期期间的不可逆性原子簇的位移引起结构放松，然后由于系统跨化的剪切带的形成而增加了势能。在接近上面的临界应变幅度后，达到屈服过渡所需的瞬态循环数量会增加。有趣的是，发现剪切方向在两个或三个维度上定期交替时，瞬态循环的数量减少，但临界应变振幅与沿单个平面的周期性剪切相同。屈服过渡后，剪切带外的材料继续应变诱导的松弛，除非剪切方向在三个维度上交替交替，并且每三个循环施加的应变幅度沿剪切带变形。
The influence of alternating shear orientation and strain amplitude of cyclic loading on yielding in amorphous solids is investigated using molecular dynamics simulations. The model glass is represented via a binary mixture that was rapidly cooled well below the glass transition temperature and then subjected to oscillatory shear deformation. It was shown that periodic loading at strain amplitudes above the critical value first induces structural relaxation via irreversible displacements of clusters of atoms during a number of transient cycles, followed by an increase in potential energy due to the formation of a system-spanning shear band. Upon approaching the critical strain amplitude from above, the number of transient cycles required to reach the yielding transition increases. Interestingly, it was found that when the shear orientation is periodically alternated in two or three dimensions, the number of transient cycles is reduced but the critical strain amplitude remains the same as in the case of periodic shear along a single plane. After the yielding transition, the material outside the shear band continues strain-induced relaxation, except when the shear orientation is alternated in three dimensions and the glass is deformed along the shear band with the imposed strain amplitude every third cycle.
