講師：Armand Barbot (Ecole Normale Superieure, France)
題目： Characterization of shear bands and plasticity in model glasses at the atomic scale
要旨：
Many phenomena remain poorly understood in amorphous materials such as
plasticity, shear banding or anisotropy upon deformation (i.e. the
Bauschinger effect). For instance, some amorphous materials such as
metallic glasses have its deformation concentrate in a persistent band
when it is deformed; but the reasons behind remain unclear. To understand
these effects, we focus here on model two-dimensional Lennard-Jones
glasses produced via different quench protocols. We are looking for a
pertinent internal variable and we are using here the measure of the
local yield stress presented in [1][2]. This technique allows us to
sample the local softness of the material in a non perturbative manner
for different loading directions on a well-control length scale.
Furthermore, the local yield stress variation upon plasticity and shear
banding shows interesting links between the shear band localization and
the structure of the material before deformation. Finally, the study of
the local yield stress after loading and unloading the glass provides
interesting informations about the induced anisotropy upon plastic deformation.
[1] S. Patinet, D. Vandembroucq, and M. L. Falk,
Connecting Local Yield Stresses with Plastic Activity in Amorphous Solids.
Phys. Rev. Lett., 117, 045501, 2016.
[2] A. Barbot, M. Lerbinger, A. Hernandez-Garcia, R. Garcia-Garcia, M. L. Falk, D. Vandembroucq, and S. Patinet.
Local yield stress statistics in model amorphous solids.
submitted to Phys. Rev.E, 2018.
