An Assessment on Failure Behaviour of Environmentally Conditioned FRP Composites: An Emphasis on Micromechanics Understanding

Abstract

Glass, Carbon and Kevlar fibers based polymeric composites were exposed to a set of different environmental situations (change in temperature,humidity,sudden flutation of temperature and humidity, sub- and cryo-environments, thermal shock, thermal spike, thermal fatigue, environmental fatigue with and/or without prior thermal conditioning including sometimes by micro-wave-assisted polymerization). The environmentally conditioned specimen were tested with 3-point bend fixture and then interlaminar shear strength(ILSS) values were calculated. These values are plotted against different parameters to index the impact and implications of various environmental parameters on the fluations of delamination strength and stiffness. The extensive Scanning Electron Microscope(SEM) study are adopted to assess and evaluate the impact of environmentally inducted defects and damages in changing or controlling the threshold value of crack initiation and propagations. One of the basic objectives is to reveal the prevailing and dominant failure behavior and modes under various environmental in-service realistic conditions.