Mechanical Characterization of EuD4TEA- and ZnS:Mn-Enhanced Composites

Triboluminescent (TL) materials are assessed as components in structural health monitoring (SHM) systems within polymer composites. Processing must be addressed due to particle characteristics such as density, morphology, and chemical makeup, all of which can affect polymer curing dynamics and thermo-mechanical properties. This study considers key processing parameters during incorporation of TL compounds into various polymers. The TL materials chosen for this study are zinc sulfide manganese (ZnS:Mn) and europium dibenzoylmethide triethylammonium (EuD4TEA). These crystals are dispersed within the liquid phase of polyvinyl ester (VE), polydimethylsiloxane (PDMS), and Dymax 9663 ultraviolet-curable (UV-curing) resins. Incorporation of the europium compound apparently slows the cure process, particularly in the UV-curing resin, while the zinc compound had a minimal effect on curing. Tensile testing shows a decrease in tensile modulus due to incorporation of TL crystals. Incorporation of the europium compound caused a 20–53% decrease in modulus; incorporation of the zinc compound caused a 7–66% decrease in modulus. Experimental results are used to create a multi-scale model using Digimat. Discrepancies in the found values may be due to sample quality (e.g. presence of voids in experimental samples)