M Feli - MSc Student, Faculty of Materials Science and Engineering, K. N. Toosi University of Technology, Tehran, Iran
R Eslami-Farsani - Associate Professor, Faculty of Materials Science and Engineering, K. N. Toosi University of Technology, Tehran
H Khosravi - PhD Student, Faculty of Materials Science and Engineering, K. N. Toosi University of Technology, Tehran, Iran

This paper represents an experimental attempt to analyze the capability of self-healing in sandwich panels based on hollow fibers. In the present study, sandwich composite plates comprising E-glass/epoxy composite laminate face-sheets and a lightweight PVC foam core were prepared. The self-healing material in the form of networks of resin and hardener was placed in the separated hollow fibers fabricating using thin-walled glass tubes. The efficacy of the self-healing system located at the face-sheet/core interface was investigated by the three-point bending test. To do so, three types of the specimens including non-damaged, damaged and healed composites were tested and the results were compared to each other. Based on the observations, it was found that self-healing phenomenon resulted from the breaking of the glass tubes during the damage stage followed by mixing of resin and hardener in the damage area. This process caused renewed connection of the core and face-sheet parts. The healing efficiency of the utilized system at the interface of the core and face-sheet components was assessed through comparing the results and occurrence of the healing as well as a significant improvement in the bending strength was observed. This work has conclusively proven that embedded resin filled hollow glass fibers at the face-sheet/core interface impart a capability for foam based sandwich panels to self-heal after damaging to restore a significant proportion of their bending strength.

Foam based sandwich panels, Self-healing materials, Face-sheet/core interface, Bending strength, Recovery