Rottler Jörg, Robbins Mark O
Princeton Institute for the Science and Technology of Materials, Princeton University, Princeton, New Jersey 08544, USA.
Phys Rev Lett. 2005 Nov 25;95(22):225504. doi: 10.1103/PhysRevLett.95.225504. Epub 2005 Nov 22.
The competing effects of slow structural relaxations (aging) and deformation at constant strain rate on the shear yield stress tau(y) of simple model glasses are examined using molecular simulations. At long times, aging leads to a logarithmic increase in density and tau(y). The yield stress also rises logarithmically with rate but shows a sharp transition in slope at a rate that decreases with increasing age. We present a simple phenomenological model that includes both intrinsic rate dependence and the change in properties with the total age of the system at yield. As predicted by the model, all data for each temperature collapse onto a universal curve.
利用分子模拟研究了简单模型玻璃中缓慢结构弛豫（老化）和恒定应变速率下的变形对剪切屈服应力τ(y)的竞争效应。在长时间下，老化导致密度和τ(y)呈对数增加。屈服应力也随速率呈对数上升，但在一个随年龄增加而降低的速率下斜率出现急剧转变。我们提出了一个简单的唯象模型，该模型既包括内在的速率依赖性，又包括屈服时系统总年龄对性质的影响。正如模型所预测的，每个温度下的所有数据都汇聚到一条通用曲线上。
