Residual stress in self-healing microcapsule-loaded epoxy

In this study, photoelastic method was used to investigate the residual stress in self-healing microcapsule-loaded epoxy. Photoelastic images show that the compressive residual stress exists in the region around the microcapsule. The shrinkage deformation of the epoxy matrix during the curing process is responsible for this residual stress. A tensile test was carried out on a self-healing microcapsule-loaded epoxy specimen with a precrack. The crack in the specimen propagated to rupture the microcapsule, which shows that the stress concentration induced by the inclusion is the main factor to affect the crack growth path and the residual stress is not important in the tensile fracture of the self-healing microcapsule-loaded epoxy specimen. (C) 2014 Elsevier B.V. All rights reserved.