A numerical study of reversible plasticity using continuum dislocation mechanics

Abstract

In this contribution, an elasto-viscoplastic fast Fourier transform-based (EVPFFT) numerical implementation of the Mesoscale Field Dislocation Mechanics (MFDM) formulation, called MFDM-EVPFFT, is applied to study the reversible plastic behavior of periodic two-phase crystalline composites with an elastoviscoplastic plastic matrix and a purely elastic second phase. Periodic laminate microstructures of this kind with different periods (i.e. sizes) are considered to examine the size dependence of the Bauschinger effect and hardening during cyclic loading. Comparisons with classic composite effects obtained with conventional crystal plasticity are discussed. Specifically, the MFDM-EVPFFT results shed light on the hardening mechanisms due to piling-up/unpiling-up of geometrically-necessary dislocations (GND) during reverse loading.

Foreword: Plasticity and Solid State Physics

“…The identification of macroscopic crystal plasticity constitutive equations from in situ HR-EBSD experimental analysis and from dislocation density simulations is also the subject of the work of Zoller et al [16], which insists on the interactions between various slip systems activated in micropillars under compression. Mesoscale field dislocation mechanics is then used by Berbenni and Lebensohn [17] to study size effects emerging from the cyclic deformation of single crystals. Finally, the simulations presented by Gelebart [18] perform the transition from single crystal to polycrystal behaviour.…”