Enhancing Interlaminar Shear Strength in Helicopter Composites

Luna Innovations Incorporated will investigate several approaches of including metallic fibers and vapor grown carbon fiber (VGCF) into glass fiber composites to improve mechanical properties including interlaminar shear strength (ILSS). The methods evaluated will minimally affect manufacturing processes anticipated for composite fabrication of helicopter components such as autoclave and RTM. For the VGCF, we plan to develop a thin film of VGCF that is included between primary reinforcing layers and disperses during the composite cure cycle. The metallic fibers approach will grow fibers in the Z direction of the composite to provide an increase in ILSS. Both of these approaches will be evaluated during the proposed Phase I effort using appropriate test specimens to determine effects on the ILSS as well as in-plane properties.