Rottler Jörg, Robbins Mark O
Department of Physics and Astronomy, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2003 Jul;68(1 Pt 1):011507. doi: 10.1103/PhysRevE.68.011507. Epub 2003 Jul 25.
We study shear yielding and steady state flow of glassy materials with molecular dynamics simulations of two standard models: amorphous polymers and bidisperse Lennard-Jones glasses. For a fixed strain rate, the maximum shear yield stress and the steady state flow stress in simple shear both drop linearly with increasing temperature. The dependence on strain rate can be described by either a logarithm or a power law added to a constant. In marked contrast to predictions of traditional thermal activation models, the rate dependence is nearly independent of temperature. The relation to more recent models of plastic deformation and glassy rheology is discussed, and the dynamics of particles and stress in small regions is examined in light of these findings.
无定形聚合物和双分散 Lennard-Jones 玻璃。对于固定的应变率，简单剪切中的最大剪切屈服应力和稳态流动应力均随温度升高而线性下降。对应变率的依赖性可以用添加到常数上的对数或幂律来描述。与传统热激活模型的预测形成鲜明对比的是，速率依赖性几乎与温度无关。讨论了与最近的塑性变形和玻璃态流变学模型的关系，并根据这些发现研究了小区域内颗粒和应力的动力学。
