PNNL

Abstract

The objective of this paper is to study the effect of fiber curvature on the elastic properties of a long-fiber composite. The study was carried out using a unit-cell homogenization approach and micromechanical modeling. In the first approach, a unit-cell with a fiber bundle was defined and used in the analysis. Appropriate boundary conditions were prescribed to extract the elastic stiffness components. The second approach made use of the Eshelby-Mori-Tanaka model to compute the stiffness of the aligned fiber composite. Fiber curvature was then accounted for through the variation of fiber orientation within a prescribed range that corresponds to a given degree of fiber curvature. It was found that curved fibers significantly affect the composite properties since they lead to a significant stiffness reduction in the longitudinal direction while relatively small increase in stiffness is achieved in the transverse direction in the plane containing the fiber tow.