Matrix-Dominated Mechanical Properties of a Fiber Composite Lamina

Abstract

Matrix-dominated mechanical properties of unidirectional fiber composite laminae were determined from hoop-wound tube specimens and cylindrical rods fabricated from both wet filament winding and prepreg material systems. Longitudinal shear modulus and strength as well as transverse Young's modulus, transverse tensile strength, and transverse compressive strength were obtained from a thin-walled tube specimen using a new fixturing design. Lamina properties are presented for several carbon fiber/epoxy composite materials. Longitudinal shear moduli were measured for both tubes and rods in torsion. Results obtained in the linear-elastic regimes above and below the glass transition temperature (Tg) of the matrix phase were compared with micromechanics predictions. Although agreement between predicted and measured shear moduli was reasonable below Tg, for some composites large discrepancies were observed at temperatures above Tg of the neat matrix material.