Effect of Moisture Absorption on Mode II Fracture Behavior of Fumed Silica Reinforced Hybrid Fiber Composite

This work aims to investigate the influence of water ingression on Mode II interlaminar fracture behavior of a fumed silica-reinforced jute-kevlar hybrid nanocomposite. Shear mode of failure is characterized by using End Notched Flexure (ENF) specimens. Thirteen different composites are prepared based on four layering sequences (i.e., Jute-Jute-Jute-Jute [JJJJ], Jute-Kevlar-Kevlar-Jute [JKKJ], Kevlar-Jute-Jute-Kevlar [KJJK], and Kevlar-Kevlar-Kevlar-Kevlar [KKKK]) and four nanofiller weight proportions (0, 1.5, 3, and 4.5%), with the aim of studying the impact of the layering sequence and nanofiller proportion. Initiation fracture toughness (G(IIC init.)) is reported for dry and wet conditions of the composites using the Simple Beam Theory (SBT) data reduction method. Among the reported stacking sequences, the stacking sequence JKKJ possesses the highest fracture-resistant material in both dry and wet conditions because of the active involvement of the fiber and matrices at the interlaminar layer resulting from interlaminar crack propagation. The water-aged composite JKKJ with a 3% nanofiller weight proportion shows the highest initiation fracture toughness (G(IIC init.)) value, 1811.4 J/m(2). The composite with the stacking sequence JKKJ and 3% nanofiller weight proportion is recommended, which is proved to be the best Mode II fracture-resistant material under wet conditions among the reported composites.