Effects of Nonuniform Crystallinity on Stress Distributions in Cross-Ply Graphite/PEEK (APC-2) Laminates

This paper presents analytical/computational results for the inplane stresses in a moderately thick, cross-ply, graphite/PEEK (APC-2) laminate accounting for effects of nonuniform PEEK crystallinity across the plate's thickness. These effects are incorporated as crystallinity-induced variations in the longitudinal modulus EL, including its nonlinear dependence on strain.