Tensile behavior and modeling of short fiber-reinforced polymer composites including temperature and strain rate effects

An experimental study was conducted to investigate the effects of temperature and strain rate on tensile behavior of polybutylene terephthalate and polyamide-6 reinforced with short glass fibers. Tension tests were performed in several mold flow directions, at a range of temperatures between −40°C and 125°C, and a range of strain rates between 5 × 10 −5 s −1 and 5 × 10 −1 s −1 . Mathematical relationships were developed to represent the stress–strain response, as well as tensile strength and elastic modulus in terms of strain rate and temperature. Time–temperature superposition principle was also employed to superimpose the effect of temperature and strain rate on tensile strength. A temperature-dependent shift factor of Arrhenius type is suggested, which is independent of the mold flow direction. Mechanisms of tensile failure were also identified from fractured surface of specimens.