Bond shear strength enhancement in FRP lap splices using CNTs and its probabilistic modelling

Abstract

Bond shear strength is one of the governing characteristics that determines the failure in FRP composite structures and needs investigation. Multi-walled carbon nanotubes (CNTs) have recently gained popularity in various structural applications to enhance mechanical properties. The improvement in the bond shear strength of glass fibre-reinforced plastic (GFRP) splices by incorporating different percentages of MWCNTs in the adhesive is experimentally investigated in this study. Experimental results reveal that the optimum amount of MWCNTs results in approximately a 30% increase in bond shear strength. The bond shear strength may vary because of differential splice geometry, material properties, etc., even though the splices are prepared using the same materials and procedures. The current research further investigates the variability in the bond shear strength of lap splices statistically using Goodness-of-fit tests, namely Kolmogorov-Smirnov (K–S), Anderson-Darling (A-D), and Chi-Square (C–S). Appropriate statistical distributions for modelling the variability in the bond shear strength are obtained. The Gumbel Max and Gumbel Min distributions are recommended to model the variability in the bond shear strength of single-lap GFRP splices without MWCNTs and with 0.1% MWCNTs. Knowledge of the variability of the bond shear strength property will help the reliability-based structural analysis of FRP composite structures.