A thermodynamically consistent phase field model for damage-healing of chemically active solids

In this paper, a thermodynamically consistent phase model for damage-healing problems is proposed, which can be applied to predict concurrent crack damage and healing behaviors of materials across different spatial and temporal scales under mechanical and chemical environments. The reaction extent and the damage phase field variable are treated as two kinds of independent variables and their coupling kinetics are developed, so that the effect of chemical reactions on the healing of crack damage can be clearly described. Furthermore, a finite element procedure for this multi-field coupling model is developed and implemented in an open-source computing platform FEniCS, enabling our model to be effectively used in engineering applications. Finally, three cases, including analysis of damage-healing coupling process, crack damage and healing of concrete, are studied using the established theoretical and numerical models. The results of the crack damage and healing of concrete are obtained and are in accordance with experimentally observed phenomena, demonstrating the applications of the present model.