Improved out-of-plane strength and weight reduction using hybrid interface composites

Carbon fiber composites with increased fiber-to-matrix bonding are often susceptible to premature failure due to the creation of overly rigid interfaces. This paper investigates the use of electrochemically functionalised carbon fibers used in novel ‘hybrid interface’ arrangements to improve out-of-plane bending. An improvement of 103.6% in single fiber interfacial shear strength (IFSS) was able to improve out-of-plane strength by 33.6% for short beam shear laminates. However, by combining both functionalised and non-functionalised fibers in complex hybrid interface arrangements such as nature inspired turtle-shell interfaces and circular patterns, mechanical performance was improved significantly. A 170.9% increase to out-of-plane strength was observed using a turtle-shell arrangement which correlated to an 8.7% reduction in composite weight as compared to control fibers.