MODELING DAMAGE IN A PLAIN WEAVE FABRIC-REINFORCED COMPOSITE-MATERIAL

A method for describing damage propagation in a woven fabric-reinforce d composite material subjected to tension or shear loading is presente d. A three-dimensional unit cell description of a plain weave graphite /epoxy fabric-reinforced composite was constructed. From this descript ion, finite element models were generated. An incremental iterating fi nite element algorithm was developed to analyze loading response. This finite element program included capabilities to model nonlinear const itutive material behavior (anisotropic plasticity), and a scheme to es timate the effects of damage propagation by stiffness reduction. Tensi on and shear loadings were modeled. Results from the finite element an alysis compared favorably with experimental data. Nonlinear shear stre ss-strain behavior of the fabric composite was shown to be principally caused by damage propagation rather than by plastic deformation of th e matrix.