Deformation and Failure Behavior of Woven Composite Laminates

Conceptually, fabric composites have some structural advantages over conventional laminates. However, deformation and failure analyses become more complex with the additional anisotropy introduced by the weaving geometry. A micromechanistic deformation model, that could realistically be incorporated into structural finite element codes, is proposed where loading direction and weave parameters are allowed to vary. Comparisons are made to previous models and experimental results for woven materials, indicating that the proposed model provides improved estimates for the linear elastic stiffness. The model further provides predictions for internal stresses in the longitudinal, transverse, and interlace regions of the woven laminate which qualitatively correspond to the experimentally observed failure mechanisms. The experimental program investigates deformations behavior and failure mechanisms of 5-harness 0/90 weave Graphite/Epoxy laminates under tension, compression, and 3-point and 4-point bending loading. Under these conditions the woven laminates exhibit orientation dependent mechanical properties and strength.