Mechanical properties of carbon fibers/epoxy composite containing anhydride self-healing material under transverse loading

In the case of presence of deep micro-cracks within the composite structures, they must be replaced. The self-healing phenomenon which is inspired from the biological systems such as vascular networks in plants or capillary networks in animals is an appropriate strategy to control the defects and micro-cracks. In the present research, by taking accounts the advantages of self-healing concept, an attempt has been made to control the micro-cracks and damages which were created in composite structures. To do so, a series of micro glass tubes were employed to provide a self-healing system. These micro-tubes were filled with epoxy resin anhydride as a healing agent. When the structure is subjected to loading conditions, some damages or micro-cracks are created. In this situation, the micro glass tubes will rupture and the healing agent flows in the damage area, leading to the elimination of the defects over a time span. The aim of this study is to find out the appropriate micro glass tubes volume fraction and healing time to obtain an efficient healing. For this purpose, glass micro-tubes containing various anhydride agent loadings of 2, 4 and 6 vol. % were incorporated in epoxy-carbon fibers composites and the bending behavior of the specimens were assessed during different time span from defect creation. The highest bending strength recovery of 84% was observed for the specimen with 4% healing agent after 8 days