FEM analysis of flexural modulus of carbon fiber monofilament considering anisotropy

Carbon fibers are highly anisotropic materials and it is necessary to understand their mechanical properties in various directions as well as their axial tensile property, for accurate prediction of mechanical properties of carbon fiber reinforced plastics (CFRP). In this study, finite element method (FEM) analysis of three-point bending test of carbon fiber monofilament was carried out on two types of carbon fibers, PAN-based and high modulus pitch-based carbon fibers. The effect of anisotropy of mechanical properties of carbon fibers on flexural modulus was studied by investigating the span length dependence of the flexural modulus obtained by FEM analysis. The experimentally determined elastic parameters, longitudinal tensile, torsional, transverse, and axial compressive moduli, were used as the analysis parameters to consider the anisotropy of carbon fiber in this study. These analyzed results of the dependence of the flexural modulus on the span length showed good agreement with the experimental ones.