Compressive Behavior of Aramid Fiber-Reinforced Pultruded Rods

Raman spectroscopy has been used to follow the tensile and compressive deformation of aramid fibers in pultruded composite rods. The deformation behavior of the rods has been compared with that of individual aramid fibers. It has been found that the deformation of the fibers in the rods is similar to that of individual isolated fibers when both are deformed in tension. For deformation in compression, however, failure of the fibers in the rods is found to take place at a lower stress than for individual fibers due probably to the cooperative formation of kink bands in the rods. These findings give a unique insight into the compressive deformation of aramid/epoxy composites and have important implications for our understanding of the compressive failure of fiber-reinforced composites in general.