Effects of Fiber Morphology in Short Fiber Reinforced Composites

The upper and lower bounds of fiber/fiber interaction effects induced by the different fiber morphologies in a short fiber reinforced composite were studied using an axisymmetric finite element (FE) model that employs a periodic hexagonal array of elastic short fibers embedded in an elastoplastic matrix. An equivalent representative volume element (RVE) was modeled to maintain vertical and horizontal constrained boundary conditions for the reduction of modeling efforts. The internal stress fields were evaluated for the ideally aligned single fiber model and compared to a staggered model. It was found that both fiber and matrix stresses in a staggered fiber model are significantly altered from those of the perfectly aligned case. Finally, the hydrostatic stresses in the matrix along the fiber/matrix interface and the evolution of matrix plasticity for each model were illustrated.