Three-dimensional finite element models and tensile properties of carbon fiber needled felt reinforced composites

Abstract

In this study, the three-dimensional finite element models of carbon fiber needled felt reinforced composites were built by using the embedded element technique and the virtual yarn method. Three sizes of samples for carbon fiber needled felt reinforced composites were designed and prepared. The tensile properties were investigated by experiments and theoretical methods, and the influences of sample size on tensile modulus were discussed. The results showed that, the longitudinal tensile moduli of carbon fiber needled felt reinforced composites decreased with the increase of sample size. Compared with the rule of mixtures and the inclusion theory, the longitudinal tensile moduli obtained by finite element method were closer to the experimental values. In addition, the transverse tensile moduli obtained by finite element method were greater than that obtained by the rule of mixtures and the inclusion theory. That was due to the orientation of some fibers had a proportion along the thickness. It was concluded that, these three-dimensional finite element models can be used to investigate the elastic properties of carbon fiber needled felt reinforced composites with different sizes.