Tensile strain‐rate response of polymeric fiber composites

Abstract The tensile behavior of unidirectional glass‐fiber polymer composites was studied at three different strain rates. Tests were performed on 0° specimens as well as off‐axis specimens at 15°, 30°, 45°, and 90° with respect to the axis of tension. The nonlinear material behavior was modeled through a viscoplastic model based on a one‐parameter plastic potential function developed elsewhere. An effective stress‐effective plastic strain curve was constructed for each strain rate imposed and fitted with a power law. Thus, the tensile stress–strain curve could be predicted in a very accurate way for every strain rate examined and various types of off‐axis specimens. The strain rate‐dependent behavior is described through a scaling law, assuming that a model parameter is a function of the imposed strain rate. Predictions of the material response at strain rates different from those initially studied were found to be successful. POLYM. COMPOS., 26:572–579, 2005. © 2005 Society of Plastics Engineers