@article{6a59a68d3db947e2b5f846b59654bd26,
title = "Self-healing of transverse crack damage in carbon fiber composites",
abstract = "Laminated fiber-reinforced composites are susceptible to transverse cracking at relatively low stresses. These cracks cause a reduction in stiffness and can lead to premature and dangerous failure modes. Here, we investigate the self-healing efficiency of carbon fiber composites in isolated transverse crack events. The composites contain solvent-filled microcapsules in an epoxy matrix toughened with 20 wt% of thermoplastic poly(bisphenol A-co-epichlorohydrin) (PBAE). Self-healing is triggered upon release of the encapsulated solvent and subsequent transport of dissolved thermoplastic into the damaged volumes. Following solvent evaporation, redistributed thermoplastic re-bonds the crack faces to heal the damage. To evaluate self-healing efficiency, we develop a new protocol which leverages digital image correlation (DIC) to compare the stress required to open and re-open a transverse crack before and after healing. Self-healing is evaluated after 2, 4, and 6 days and compared to control specimens that are healed thermally. We report a self-healing efficiency of up to 57% after 6 days with just 1 vol% microcapsule concentration in a high glass transition temperature (179 °C) carbon fiber-reinforced composite.",
keywords = "Digital image correlation, Multifunctional composites, Polymer-matrix composites (PMCs), Self-healing, Transverse cracking",
author = "Chang, {Kelly M.} and Sottos, {Nancy R.}",
note = "The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Nancy R. Sottos reports financial support was provided by Air Force Office of Scientific Research.This work was funded by Phase II of the University of Illinois Center of Excellence: Self-healing to Morphogenic Manufacturing supported by the Air Force Office of Scientific Research (AFOSR Grant No. FA9550-20-1-0194). The authors would like to acknowledge the Beckman Institute and the Imaging Technology Group at the University of Illinois for access to their characterization facilities. The authors would also like to thank undergraduate research assistants Enola Ma, Aiden Kamber, and Alex Kosyakov for their help with microencapsulation. Dr. Chris Montgomery, Dr. Sang Yup Kim, and Dr. Chaimongkol Saengow also provided helpful discussion. This work was funded by Phase II of the University of Illinois Center of Excellence: Self-healing to Morphogenic Manufacturing supported by the Air Force Office of Scientific Research (AFOSR Grant No. FA9550-20-1-0194 ). The authors would like to acknowledge the Beckman Institute and the Imaging Technology Group at the University of Illinois for access to their characterization facilities. The authors would also like to thank undergraduate research assistants Enola Ma, Aiden Kamber, and Alex Kosyakov for their help with microencapsulation. Dr. Chris Montgomery, Dr. Sang Yup Kim, and Dr. Chaimongkol Saengow also provided helpful discussion.",
year = "2023",
month = sep,
day = "29",
doi = "10.1016/j.compscitech.2023.110158",
language = "English (US)",
volume = "242",
journal = "Composites Science and Technology",
issn = "0266-3538",
publisher = "Elsevier B.V.",
}