  Chemo-mechanical coupled systems have been a subject of interest for many
decades now. Previous attempts to solve such models have mainly focused on
elastic materials without taking into account the plastic deformation beyond
yield, thus causing inaccuracies in failure calculations. This paper aims to
study the effect of stress-diffusion interactions in an elastoplastic material
using a coupled chemo-mechanical system. The induced stress is dependent on the
local concentration in a one way coupled system, and vice versa in a two way
coupled system. The time-dependent transient coupled system is solved using a
finite element formulation in an open-source finite element solver FEniCS. This
paper attempts to computationally study the interaction of deformation and
diffusion and its effect on the localization of plastic strain. We investigate
the role of geometric discontinuities in scenarios involving diffusing species,
namely, a plate with a notch/hole/void and particle with a void/hole/core. We
also study the effect of stress concentrations and plastic yielding on the
diffusion-deformation. The developed code can be from
https://github.com/mrupeshkumar/Elastoplastic-stress-diffusion-coupling
