Effect of intralaminar hybridization on mode I fracture toughness of natural fiber-reinforced composites

Abstract

The main objective of this work was to investigate the effect of intralaminar hybridization on the mode I fracture toughness of epoxy composites based on jute and sisal fabrics. Four types of composites were produced by the hand layup technique: sisal (S), sisal + curaua (S + C), jute (J) and jute + curaua (J + C). Double cantilever beam (DCB) tests were performed, and the modified beam theory (MBT) method and three different data criteria (i.e. the deviation from linearity (NL), the 5% offset/maximum load (5%/Max) and visual observation (VIS)) were used to evaluate the mode I fracture toughness (GIc). It was found that the GIc of S + C and J + C composites increased by hybridization of pure sisal and jute fabrics and that the intralaminar hybridization limited the crack propagation. An X-ray microcomputed tomography (µCT) equipment was used to visualize the delamination and the form of the front of cracks inside the hybrid composites.