Modeling Damage in a Plain Weave Fabric-Reinforced Composite Material

A method for describing damage propagation in a woven fabric-reinforced composite material subjected to tension or shear loading is presented. A three-dimensional unit cell description of a plain weave graphite/epoxy fabric-reinforced composite was constructed. From this description, finite element models were generated. An incremental iterating finite element algorithm was developed to analyze loading response. This finite element program included capabilities to model nonlinear constitutive material behavior (anisotropic plasticity), and a scheme to estimate the effects of damage propagation by stiffness reduction. Tension and shear loadings were modeled. Results from the finite element analysis compared favorably with experimental data. Nonlinear shear stress-strain behavior of the fabric composite was shown to be principally caused by damage propagation rather than by plastic deformation of the matrix.