In this study, healing of conventional non-shape memory syntactic foam embedded with shape memory polyurethane fibers was investigated per the biomimetic close-then-heal strategy. The syntactic foam was made of epoxy matrix dispersed with 30% by volume of glass microballoons, 5% by volume of shape memory polyurethane fibers, and three levels of thermoplastic healing agent (5%, 10%, and 15% by volume). Notched beam specimens were prepared and fractured by tension to create macroscopic cracks. Three levels of tensile stresses (26.5, 24.5, and 22.5 kPa) were applied to the fractured beam specimens during healing, in order to evaluate the healing capability of the composite under in-service conditions. It is found that the tensile stress level and healing agent content have a significant effect on the healing efficiency. Subjected to 22.5 kPa of tensile stress, the healing efficiency determined by peak tensile load is as high as 90%.
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