Saw Shibu, Abraham Sneha, Harrowell Peter
School of Chemistry, University of Sydney, Sydney, New South Wales 2006, Australia.
Phys Rev E. 2016 Aug;94(2-1):022606. doi: 10.1103/PhysRevE.94.022606. Epub 2016 Aug 15.
We demonstrate that irreversible structural reorganization is not necessary for the observation of yield behavior in an amorphous solid. While the majority of solids strained to their yield point do indeed undergo an irreversible reorganization, we find that a significant fraction of solids exhibits yield via a reversible strain. We also demonstrate that large instantaneous strains in excess of the yield stress can result in complete stress relaxation, a result of the large nonaffine motions driven by the applied strain. The empirical similarity of the dependence of the ratio of stress over strain on the nonaffine mean-square displacement to that for the shear modulus obtained from quiescent liquid at nonzero temperature supports the proposition that rigidity depends on the size of the sampled configurational space only and is insensitive to how this space is sampled.
我们证明，对于观察非晶态固体中的屈服行为而言，不可逆的结构重组并非必要条件。虽然大多数被拉伸至屈服点的固体确实会经历不可逆的重组，但我们发现相当一部分固体通过可逆应变表现出屈服。我们还证明，超过屈服应力的大的瞬时应变会导致完全的应力松弛，这是由所施加应变驱动的大的非仿射运动的结果。应力与应变之比对应于非仿射均方位移的依赖性与在非零温度下从静态液体获得的剪切模量的依赖性在经验上的相似性，支持了这样的观点：刚性仅取决于所采样的构型空间的大小，并且对该空间的采样方式不敏感。
