Professor and research associate, Robert R. McCormick School of Engineering and Applied Science, Northwestern University, Evanston, IL
Damage development under monotonic loading was studied in five cross-ply graphite/epoxy laminates. The laminates exhibited three characteristic ranges of varying stiffness. The first range is linear elastic and is characterized by the absence of any measurable damage. The second range is one of decreasing stiffness and corresponds to transverse matrix cracking in the 90° layer up to the characteristic damage state (CDS). The third range is a nearly linear one of stabilized or even slightly increasing stiffness. Ultimate failure was governed by the ultimate tensile strain in the 0° plies with small variations attributed to residual stresses, statistical scatter and local strain concentration.
Paper ID: CTR10185J