Evaluation of mechanical properties of noncircular carbon fiber reinforced plastics by using XFEM-based computational micromechanics

The aim of this study is to investigate the mechanical properties of noncircular carbon fiber reinforced plastics (CFRPs). For an efficient study of various CFRP microstructures, this study combines an extended finite element method (XFEM), a homogenization method, and a Monte Carlo method and establishes XFEM-based computational micromechanics. This scheme made it possible to simulate CFRPs having various microstructure without remeshing and resetting boundary conditions. In the verification against general circular CFRPs, it was revealed that the developed scheme has a sufficient accuracy for the prediction of the homogenized elastic constants including their stochastic nature. Finally, the effects of the cross-sectional fiber shape on the macroscopic CFRP properties were examined. Among the five fiber shapes (circular, elliptical, two-lobed, triangular, and square), the square CFRP exhibited the best transverse mechanical properties. Therefore, it was concluded that the noncircular carbon fibers have a potential to enhance the macroscopic mechanical performance of CFRPs.