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

S. Ravi, Indian Institute of Technology Kanpur
N. G.R. Iyengar, Indian Institute of Technology Kanpur
N. N. Kishore, Indian Institute of Technology Kanpur
A. Shukla, Kyushu University, Research Institute for Applied Mechanics


Experiments have been carried out to study the damage fracture growth and the associated damage mechanisms in woven glass fiber reinforced polyester composites. The initiation and propagation history ofthe damage has been recorded at few microsecond intervals using a high speed Cranz-Schardin camera. The images obtained are analyzed using IDRISI, an image processing tool. Three different fiber volumefractions, 2.4, 5.3 and 33.0 percent are considered. The influence of notch orientation are studied by varying the initial notch orientation between 0° and 45°. On the basis of the studies, it isobserved that irrespective of initial notch orientation, the damage propagates in a direction perpendicular to the loading direction. For low fiber volume fractions, the damage is in the form of matrixcracking and interface debonding while delamination dominates for specimens with high fiber volume fractions. The damage velocity in low fiber volume fraction specimens are found to be higher than the terminalvelocity of the crack in unreinforced polyester resin. Fractographic studies are also carried out and the results are presented. © 2000 Taylor & Francis Group, LLC.