Study of the damage behavior of T800 carbon fiber/epoxy resin composites after low-velocity impact under thermo-oxidative aging

Here, the effect of thermo-oxidative aging on domestic T800 carbon fiber/epoxy resin composites was studied using mass loss rate curves, interface morphology, infrared spectroscopy, and dynamic mechanical property analysis. The composites were subjected to thermo-oxidative aging tests after low-velocity impact. Then, the effect of environmental factors on the damage area of the composites and the compression performance after impact were investigated. The results showed that the composites underwent physical and chemical aging at 185°C. Due to the short aging time, the mass loss rate slowly increased. After aging, thermo-oxidative aging caused the matrix to crack, and the sample cracks that formed after impact expanded, and the damage area also slightly increased. The residual compressive strength of the material fluctuated due to the competing reinforcing and destructive effects of the composite during thermo-oxidative aging; however, aging had little effect on the impact damage morphology and compression failure mode. Upon extending the aging time, thermo-oxidative aging caused the tanδ peak to gradually shift to a higher temperature, and the glass transition temperature ( Tg) increased.