Effect of Matrix Ductility on Elastic—Plastic Interlaminar Stresses in Thermoplastic AS4/PEEK Composite Laminates

Abstract

Using three orthotropic elastic finite element models with elastic and elastic—plastic PEEK resin-rich layers included, three-dimensional elastic—plastic analyses of interlaminar stresses in AS4/PEEK thermoplastic composites under tensile loading for [0/90]s, [0/±45/90] 2s, and [±25]s4 laminates are presented, in order to ascertain the influence of matrix plasticity upon the free-edge effect in AS4/PEEK laminate. The nonlinear tension behaviors of the whole laminate are predicted by means of the above numerical models and compared with experimental results in detail. The applicability of these FE models with elastic—plastic resin layers models is discussed.