A Fully Coupled Chemomechanical Formulation with Chemical Reaction Implemented by Finite Element Method

Based on the irreversible thermodynamics, a fully coupled chemomechanical model, i.e., the reaction-diffusion-stress model, is proposed and implemented numerically into the finite element method (FEM) with user-defined element (UEL) subroutines in abaqus. Compositional stress and growth stress are induced by the diffusion and chemical reactions in the solid, and in turn, both the diffusion and chemical reactions are stress-dependent. By providing specialization of the chemical reaction and free energy function, the specialized constitutive equations are introduced, which are highly coupled and nonlinear. The FE formulations are derived from the standard Galerkin approach and implemented via UEL subroutines in abaqus. Several illustrative numerical simulation examples are shown. The results demonstrate the validity and capability of the UEL subroutines, and show the interactions among mechanical deformation, diffusion, and chemical reaction.