Structural changes and viscoplastic behavior of a generic embedded-atom model metal in steady shear flow.
We study equilibrium and nonequilibrium properties of a simple "generic embedded-atom model" (GEAM) for metals. The model allows to derive simple analytical expressions for several zero-temperature constitutive properties--in overall agreement with real metals. The model metal is then subjected to shear deformation and strong flow via nonequilibrium molecular dynamics simulation in order to discuss the origins of some qualitative properties observed using more specific embedded-atom potentials. The "common neighbor analysis," based on planar graphs is used to obtain information about the transient structures accompanying viscoplastic behavior on an atomic level. In particular, pressure tensor components and plastic yield are investigated and correlated with underlying structural changes. A simple analytical expression for the isotropic pressure at finite temperatures is proposed. A nonequilibrium phase diagram is obtained by semianalytic calculation.
Institut für Theoretische Physik, PN 7-1, Fakultät II, Technische Universität Berlin, D-10623 Berlin, Germany. stanovic@itp.physik.tu-berlin.de
Igor
I
Stankovic
Siegfried
S
Hess
Martin
M
Kröger