2013/10/10 by Penghui Cao, Harold S. Park, Xi Lin · 1 citation
Chemistry · Engineering · Materials Science · Physics and Astronomy · #Amorphous metal #Amorphous solid #Chemistry #Composite material #Condensed matter physics #Crystallography #Deformation (meteorology) #Material Dynamics and Properties #Materials science #Metallic Glasses and Amorphous Alloys #Nucleation #Physics #Quasistatic process #Rheology #Shear (geology) #Shear matrix #Shear rate #Shear stress #Strain rate #Theoretical and Computational Physics #Thermodynamics #cond-mat.soft #cond-mat.stat-mech
paper · pdf · doi:10.1103/physreve.88.042404
published as Phys. Rev. E. 88, 042404 (2013)
openalex publication_date 2013/10/10 · arxiv created 2013/10/25 · arxiv updated 2013/10/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We couple the recently developed self-learning metabasin escape algorithm, which enables efficient exploration of the potential energy surface (PES), with shear deformation to elucidate strain-rate and temperature effects on the shear transformation zone (STZ) characteristics in two-dimensional amorphous solids. In doing so, we report a transition in the STZ characteristics that can be obtained through either increasing the temperature or decreasing the strain rate. The transition separates regions having two distinct STZ characteristics. Specifically, at high temperatures and high strain rates, we show that the STZs have characteristics identical to those that emerge from purely strain-driven, athermal quasistatic atomistic calculations. At lower temperatures and experimentally relevant strain rates, we use the newly coupled PES + shear deformation method to show that the STZs have characteristics identical to those that emerge from a purely thermally activated state. The specific changes in STZ characteristics that occur in moving from the strain-driven to thermally activated STZ regime include a 33% increase in STZ size, faster spatial decay of the displacement field, a change in the deformation mechanism inside the STZ from shear to tension, a reduction in the stress needed to nucleate the first STZ, and finally a notable loss in characteristic quadrupolar symmetry of the surrounding elastic matrix that has previously been seen in athermal, quasistatic shear studies of STZs.