Investigation On Microcapsule Self-Healing Mechanism Of Polymer Matrix Composites Based On Numerical Simulation

Since delamination always occurs in the laminate structures of fiber reinforced polymer composites in engineering applications, developing self-healing composites has become more and more important nowadays, especially for large-scale composite equipment, which is difficult to maintain when in service. In this paper, the micromechanical finite element (FE) models are developed for the polymer matrix composites containing self-healing microcapsules. Based on mesoscale FE simulation and cross reference to related experimental results, we firstly reveal the rupture mechanism of microcapsules, in which the interaction between the microcapsules and microcracks propagated in the resin matrix is investigated by using the extended finite element method in ABAQUS. The mesoscale characteristics of the self-healing agent, dicyclopentadiene, during the healing process, are revealed with the help of the fluid-solid coupling FE module. Especially, the dynamic filling mechanism of the self-healing agent within the microcrack planes is physically interpreted by the use of the capillary effect and contact angle principle. Finally, the healing efficiencies of self-healing composites with different microcapsule sizes and volume fractions are quantitatively evaluated via the virtual mechanical tests of fracture toughness. To be emphasized is that most of the simulation results obtained in this work have exhibited good agreements with the corresponding experimental data, showing a robust reliability of our FE models.