Comparison of Tensile Properties of Carbon/Epoxy Composite Materials with Different Fiber Orientation Using Digital Image Correlation

Abstract

Due to its remarkable qualities, carbon fiber epoxy composite sandwich panels are used in a variety of engineering applications. The goal of this research is to use tensile testing and a full-field non-contact 3D Digital Image Correlation (DIC) method to characterize carbon fiber reinforced composite sandwich panels with varied fiber orientations (0°/90°and ± 45°). The tested materials were composed of carbon fiber prepregs with epoxy resin systems and Aramid synthetic fiber. The properties of the materials were determined using full-field data derived from 3D DIC measurements and a set of experiments by according to ASTM standards. Values of maximum stress and strain at entire areas, break stress and strain, and toughness at entire areas and, modulus of elasticity of both structures were compared. The adherend's full-field, out-of-plane deformation, strain distribution, and strain evolution along the bond line were captured using a digital image correlation method, allowing the fracture mechanism to be visually defined. Since DIC produces the displacement field, the strain field must be deduced from it. The orientation of the fibers had a significant impact on the tensile properties of the tested materials. The results revealed that the specimen with 0°/90°fiber orientation had higher break stress and brittle fracture, whereas the specimen with ± 45°fiber orientation twisted in the fiber direction had higher elongation values while carrying the applied load. In order to complement previously obtained results, scanning electron microscopy (SEM) analysis of the fibers and core, as well as fracture surfaces was performed.