Effect of pristine MWCNTs on the fatigue life of GFRP laminates-an experimental and statistical evaluation.

This research investigation explores the dispersion effectiveness of P c (percolation threshold), 0.5, 1.0, 1.5 and 2.0 vol fraction of MWCNTs (Multiwalled Carbon Nanotubes) in epoxy using UV–Vis (Ultraviolet Visible Region) spectroscopy, their effect on the rheological properties of the solvent and mechanical properties of the fabricated NCs (nanocomposites). Addition of higher amount of MWCNTs increased the absorptivity of the solution in UV–Vis region depicting higher number of untangled and individual MWCNTs in the solution. However, post ultrasonication reagglomeration of these nanoparticles was found to be inevitable and its rate depended upon the amount of nanotubes in the epoxy. Addition of MWCNTs increased the viscosity of the polymer but they were found to be unable to diminish its shear thinning behaviour. Once proper dispersion of the nanotubes in the epoxy was confirmed by UV–Vis spectroscopy, their NCs with (three-phased) and without (two-phased) glass fibers were prepared. Tensile tests asserted that an increase in MWCNT content in the matrix increase toughness of the prepared nanocomposites. Individual CNTs contributed to the ultimate strength of the laminates and their aggregates enhanced the strain to failure. Addition of MWCNTs in GFRP (glass fiber reinforced polymer) laminates not only increased their cycles to failure but also imparted large coefficient of variation in their fatigue life. Reliability analysis and survival probability of the concerned laminates were included for their design considerations. [ABSTRACT FROM AUTHOR]