High strain rate properties of balanced angle-ply graphite/epoxy composites

The vast differences in strength, ultimate strain and modulus during high strain rate deformation of materials have been a very long-standing subject of engineering interest. The present study is carried out in order to understand the effect of fiber orientations on compressive dynamic properties of balanced angle-ply IM7/8551-7 graphite/epoxy composites using the Split Hopkinson Pressure Bar at varying strain rates, ranging from 500 to 1500 s(-1). The ultimate stress-strain behavior with respect to change in strain rates for various fiber orientations has been studied in depth. Additionally, optical microscopic images of fracture surfaces show that delamination caused by edge effects is the prominent mechanism of failure. This research provides important data and understanding of composite material structures in high strain rate applications. (C) 2003 Elsevier Science Ltd. All rights reserved.