Institute for Theoretical Physics, Institute of Physics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
Phys Rev E. 2016 Jan;93(1):011001. doi: 10.1103/PhysRevE.93.011001. Epub 2016 Jan 28.
We propose a theoretical framework within which a robust micromechanical definition of precursors to plastic instabilities, often termed soft spots, naturally emerges. They are shown to be collective displacements (modes) z[over ̂] that correspond to local minima of a barrier function b(z[over ̂]), which depends solely on inherent structure information. We demonstrate how some heuristic searches for local minima of b(z[over ̂]) can a priori detect the locus and geometry of imminent plastic instabilities with remarkable accuracy, at strains as large as γ_{c}-γ∼10^{-2} away from the instability strain γ_{c}. Our findings suggest that the a priori detection of the entire field of soft spots can be effectively carried out by a systematic investigation of the landscape of b(z[over ̂]).
我们提出了一个理论框架，在这个框架中，通常称为软点的塑性失稳前体的稳健微观力学定义自然出现。它们被证明是对应于势垒函数 b(z[over ̂])局部极小值的集体位移（模式）z[over ̂]，而势垒函数 b(z[over ̂])仅取决于固有结构信息。我们展示了一些启发式搜索 b(z[over ̂])的局部极小值的方法，如何能够以惊人的精度预先检测到即将发生的塑性失稳的位置和几何形状，应变高达 γ_{c}-γ∼10^{-2}，远低于失稳应变 γ_{c}。我们的发现表明，可以通过系统地研究 b(z[over ̂])的地形来有效地进行整个软点场的预先检测。
