Mechanical behavior of large-rupture-strain (LRS) polyethylene naphthalene fiber bundles at different strain rates and temperatures

Abstract

This paper presents the results of an experimental study aimed at investigating the effects of strain rate and temperature on the tensile mechanical properties of polyethylene naphthalene (PEN) fiber bundles by using a drop-weight impact system. A total of 65 specimens with a gauge length of 25 mm were prepared and tested. The test variables included five different strain rates (1/600, 40, 80, 120 and 160 s−1) and five different temperatures (−50, −25, 0, 25 and 50 °C). The results indicated that the tensile strengths and elastic moduli of the specimens increased with the strain rate, whereas the failure strain decreased and the toughness remained almost unchanged with the increase of the strain rate. The tensile strength, toughness and failure strain initially improved and then reduced with an increasing temperature from − 50 °C to 50 °C. A Weibull distribution model was implemented to describe the degree of variability in the tensile strength of PEN fiber bundles for future use.