Effects of tow arrangements on the homogenized response of carbon fiber woven composites

Abstract

A set of micro-mechanical analyses is carried out to investigate the sensitivity of the homogenized response of two-ply carbon fiber woven composites on relative positioning of tow arrangements. In this paper, first, we present a convergence study to validate the applicability of the characteristic unit cell to capture the macroscale mechanical response of the composite. The study showcases the capacity of our models to capture the macroscale mechanical properties at different microscopic resolutions of the macroscale. The effects from phase different tow arrangements are then analyzed to quantify the mechanical response variability at the macroscale. Different tow arrangements considered in this work naturally stems from the relative inter-ply sliding at the manufacturing stage of woven composites. We consider several tow arrangements that can be interpreted as intermediate configurations between the two extremes; fiber in-phase and out-of-phase. Tows are assembled and constrained systematically to resemble different tow arrangements for the subsequent multiscale modeling. Corresponding macroscopic ABD stiffness matrices are extracted using the principle of virtual work, whereby the unit cell deformation is homogenized using periodic boundary conditions. The obtained results not only quantify the variability in A and D sub-matrices of the ABD stiffness matrix, but also explain possible reasons for the observed deviations between experimental and numerical results.