SIMULATION OF SELF-HEALING PROCESSES IN MICROCAPSULE BASED SELF-HEALING POLYMERIC SYSTEMS

Self healing materials are becoming more and more important for the construction of mechanical components due to their ability to detect and heal failures and cracks autonomously. Especially in polymers and polymer-composites, where the component can loose a high rate of strength and durability due to micro cracks, those damages are nearly impossible to repair from outside. Thus, self healing ability is a very effective approach to extend the lifetime of polymer-made components. In view of the numerical simulation of such self healing effects we develop a thermodynamically consistent macroscopic 5-phase model within the theoretical framework of the Theory of Porous Media. The model consists of the following different phases: solid (matrix material) with dispersed catalysts, liquid (healing agents), healed material and gas (air inside the cracks). The increase of damage is driven by a discontinuous damage evolution equation. Furthermore, a mass exchange between the liquid-like healing agents and the solid-like healed material, i.e. the change of the aggregate state from liquid healing to solid healed material, describes the healing process. The onset of the healing process is associated with the break open of the microcapsules in connection with the subsequent motion of the liquid healing agents. A numerical example of the simulation of damage and healing processes in polymers, is presented in order to show the applicability of the model.