Moisture Sorption of Epoxy Composites Reinforced with Aligned and Notched Triangular Bars
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Moisture diffusion in acid anhydride-cured epoxy matrices reinforced with aligned and notched triangular bars has been investigated. The reinforcing bars were first treated with molded and cured vinyl ester resin before their manual assembling. Gravimetric experiments were performed on epoxy composites fully immersed in water at 80°C for 1200 h. Weight uptake curves showed that the composites had suffered limited material degradation after an initial stage of moisture sorption; another sorption stage was observed after this degradation phase. Based on the initial sorption stage, the moisture diffusion behavior in composites is found to be independent of the orientation and alignment of reinforcing bars. This result is confirmed by transient 3D finite-element simulations. The numerical results are in close agreement with experimental data for the initial sorption stage.
Keywordspolymer composite notched triangular bar diffusion finite-element simulation moisture sorption
The authors would like to acknowledge the Hitachi Scholarship Foundation for the financial support. The authors would also like to express their deepest gratitude to Dr. Saiko Aoki for the procurement of materials and the experimental setup, and to Dr. Hideki Sembokuya for the fabrication of metallic molds for curing and forming notched triangular vinyl ester bars.
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