Influence of fiber volume fraction on dynamic damage in woven glass fabriccomposites: An experimental study

Experiments have been carried out to study the damage fracture growth and t he associated damage mechanisms in woven glass fiber reinforced polyester c omposites. The initiation and propagation history of the damage has been re corded at few microsecond intervals using a high speed Cranz-Schardin camer a. The images obtained are analyzed using IDRISI, an image processing tool. Three different fiber volume fractions, 2.4, 5.3 and 33.0 percent are cons idered. The influence of notch orientation are studied by varying the initi al notch orientation between 0 degrees and 45 degrees. On the basis of the studies, it is observed that irrespective of initial notch orientation, the damage propagates in a direction perpendicular to the loading direction. F or low fiber volume fractions, the damage is in the form of matrix cracking and interface debonding while delamination dominates for specimens with hi gh fiber volume fractions. The damage velocity in low fiber volume fraction specimens are found to be higher than the terminal velocity of the crack i n unreinforced polyester resin. Fractographic studies are also carried out and the results are presented.