Experimental Characterization of Mode I Fracture Toughness of Reinforced Carbon Fiber Laminate with Nano-Cellulose and CNT Additives

Effective treatment of carbon fiber components to improve delamination resistance is vital to the application of such materials since delamination is one of the biggest concerns regarding the use of composites in the aerospace sector. Due to the significant application benefit gained from increased stiffness to density ratio with composite materials, innovative developments resulting in improved through-thickness strength have been on the rise. The inherent anisotropy of composite materials results in an added difficulty in designing structural elements that make use of such materials. Proposed techniques to improve the through-thickness strength of laminar composites are many and varied; however all share the common goal of improving inter-laminar bond strength.

This research makes use of novel materials in the field of wet flocking and Z-pinning. Cellulose nanofibers (CNFs) have already demonstrated excellent mechanical properties in terms of stiffness and strength, originating at the nano-scale. These materials were introduced into the laminate while in a sol-gel suspension in an effort to improve load transfer between laminate layers. The effect of CNFs as lightweight renewable reinforcement for CFRPs will be investigated. Carbon nanotube (CNT) additives were also considered for their beneficial structural properties.