Abstract
A method to predict the time response of unidirectional glass fiber and plain woven glass cloth reinforced polyester laminates was described. The short term (20 minutes duration) creep test results of strip tension specimens with the load at various angles to the fiber direction were reported and compared to the analytical results. For the unidirectional laminates, it was shown that the materials were elastic at all stress levels when the fibers were in the load direction. On the other hand, when the load transverse to the fibers the viscoelastic response varying from a small amount at low stress level to a large amount at high stress level appeared even at room temperature. For off-axis specimens and plain woven laminates, the response was similar to the latter.
Furthermore, the numerically predicted results were compared with the experimental results. The results showed that only two material informations were needed to predict the viscoelastic response of the composites: One is the viscoelastic response of the matrix resin and the other is the elastic constants of the glass fiber.
