Comparison of Tensile Properties of Carbon Fiber, Basalt Fiber and Hybrid Fiber Reinforced Composites Under Various Strain Rates

Carbon fiber reinforced epoxy (CFRE) and basalt fiber reinforced epoxy (BFRE) are used widely in automotive, navy due to their excellent mechanical performance. In this study, the effects of strain rate sensitivity of CFRE, BFRE and their mixtures were studied. Five strain rate (quasi-static: 0.0017 s(-1), dynamic state: 0.1 s(-1), 10 s(-1), 100 s(-1), 150 s(-1)) were applied. The cross-section of the fractured specimens was analyzed. Results showed that the hybrid composites all exhibited stacking sequence sensitivity. In the quasi-static state, the peak forces of two hybrid structures were between that of BFRE and CFRE, in which H1 and H2 are improved by 3 MPa and 29 MPa, compared to BFRE, respectively. While in the dynamic state, the mechanical properties of three hybrid structures were all worse than those of BFRE and CFRE. The hybrid composites were also sensitive to strain rates. When the loading speed increased from quasi-static to dynamic state, the peak forces of five structures all increased a lot. However, the three structures (BFRE, H1, H2) exhibited strain rate sensitivity, when the stretch speed increased in the dynamic range. The five structures all showed stratification after stretching. Compared with the cross-section after quasi-static stretching, the cross-section after dynamic stretching had fewer microcracks. The tight combination of fibers and resin could explain the sequence sensitivity of three hybrid structures.