Dynamic In-Plane Shear Mechanical Behavior of Carbon Fiber/Epoxy Composite at Different Temperatures

The dynamic in-plane shear behavior of a carbon fiber/epoxy composite at different temperatures (-30, 25, 55, and 85 degrees C) was analyzed. A split Hopkinson tensile bar system with high and low-temperature chambers was applied. The study focuses on testing +/- 45 degrees symmetric carbon fiber laminated composite specimens to obtain the in-plane stress-strain curves and failure morphologies. The results revealed that the in-plane shear properties of the carbon fiber/epoxy composite are influenced by both strain rate and temperature. The stress-strain curves exhibit nonlinear characteristics at different temperatures and strain rates, with the nonlinearity becoming more pronounced as the temperature increases. Furthermore, the research indicates that in-plane shear strength and shear modulus tend to increase with higher strain rates and decrease with rising temperatures. To analyze the failure morphologies and mechanisms, scanning electron microscopy observations were conducted on the test specimens. To incorporate the effects of strain rate and temperature, the study proposes formulas for in-plane shear strength and shear modulus. The formulas proposed describe effectively the experimental data obtained.