Dynamic tensile properties of flax fiber reinforced polymer composites

Abstract

Flax fibers have been widely used as reinforcing materials due to the growing demand for the development of sustainable materials. They are cost-effective and have excellent mechanical properties. In this study, the dynamic tensile properties of flax FRP coupons were tested using an Instron VHS high rate testing system. The effect of strain rate on the failure process, failure modes, tensile strength, failure strain, and Young’s modulus of flax FRP coupons were discussed and analyzed within the strain rate less than 164.2 s−1. The failure process at different strain rates were captured by a high-speed camera. It was observed that the specimen failed with only one cross-sectional fracture at a relatively low strain rate. At a relatively high strain rate, more than one fracture was observed. The experimental results indicated that the dynamic tensile strength increased, failure strain decreased, and Young’s modulus remained almost unchanged when the strain rate was less than 41.3 s−1. As it was over 41.3 s−1, the dynamic tensile strength, failure strain, and Young’s modulus had a prominent rise. To describe the dynamic tensile strength, failure strain, and Young’s modulus at a certain strain rate, empirical equations based on the experimental data were proposed for reference.