The objective of this study is to develop three dimensional (3D) impact self-sensing composites capable of localizing impact damage in through-the-thickness direction. The 3D impact self-sensing composites (3D-ISSC) are designed by embedding fracto-mechanoluminescent (FML) crystals in cells of honeycomb-cored fiber reinforced polymer (FRP) structural composites. FML crystals were shown to emit light resulting from cleavage of crystalline structures due to external mechanical stimuli. Unlike other conventional sensor networks, without supplying external electrical source, the 3D-ISSC is envisioned to monitor impact occurrences and detect damage. Instead, the emitted light will be utilized for informing severity of impact occurrences and 3D locations of the impact damage. First, FML europium-doped dibenzoylmethide triethylammonium (EuD4TEA) crystals are synthesized. Second, the synthesized EuD4TEA crystals are embedded in the honey-cored FRP structural composites to fabricate 3D-ISSC. Third, to validate its 3D self-sensing capability, Kolsky bar is employed to apply high strain-rate compressive loading to simulate impact occurrences while taking high-speed video footage for quantifying intensity of FML light emission through image processing technique.
Sustainable self-healing at ultra-low temperatures in structural composites incorporating hollow vessels and heating elements
