Flexure creep properties of E-glass reinforced polymers

The long-term creep behavior and creep-rupture properties were investigated for two systems of E-glass reinforced polymer composites: E-glass/polyurethane composite and E-glass/epoxy composite. The two composite systems showed similar short-term mechanical properties, however their long-term creep properties were quite different. The E-glass/polyurethane system exhibited tertiary creep leading to rupture within a few hours when subjected to about 60% of its flexural strength while the E-glass/epoxy endured months of loading at 60% of its flexural strength before rupture at 50 °C. The findings in this study indicate that creep testing is essential in material characterization and material selection, that the three-point flexure test can be used as a quick test method to determine creep-rupture properties, and that creep-rupture is highly influenced by the type of matrix and the fiber/matrix interface.