Mechanics of Laminated Composites Containing Wavy Fibers

Abstract

Fiber waviness is fabrication induced defects in composite materials. Others have used the terms "fiber imperfections" to refer to these manufacturing defects. This defect is shown in Figure 1. It is quantified geometrically by A/L, the ratio of amplitude A to wavelength L. Fiber waviness defects have been observed to occur in, or through the thickness of, the plane of lamination. The present research involves the development of mathematical model and numerical solution methods to investigate the effect of fiber waviness on the elastic behavior and stability of composite laminate. A theoretical model is developed for a unidirectional lamina whose fiber is sinusoidal in the plane of the lamina. This model predicts the elastic properties of the lamina, bending stiffness of laminate, and critical buckling load as function of A/L.