MESOSCALE MODELING AND HOMOGENIZATION OF WOVEN CARBON FIBER COMPOSITES

Abstract

In this study, we investigated the impact of varying boundary conditions and simulation domain size on the calculation of homogenized elastic moduli, Poisson’s ratio, thermal expansion, and cure shrinkage for woven carbon composites. The boundary conditions of interest included kinematically uniform (KUBC), statically uniform (SUBC), and periodic (PBC). Stress and strain distributions were compared across the entire simulation domain and for sub-volume regions of interest when the domain size was increased. Additionally, homogenized properties were quantified and compared across varying domain sizes. Key results show that effective moduli determined using KUBCs and SUBCs provide upper and lower limits that bounded values determined using PBCs. However, for out-of-plane thermal expansion and cure shrinkage, the effective values were not bounded by the values determined using KUBCs and SUBCs. Thermal expansion coefficients determined using KUBCs and SUBCs were underpredicted compared to values obtained from PBCs. Similarly, cure shrinkage determined using KUBCs and SUBCs were overpredicted compared to values obtain from PBCs. Lastly, it was shown that homogenized values obtain using PBCs could be well approximated using KUBCs or SUBCs with an increased domain size. Specifically, homogenized properties determined using KUBCs or SUBCs exhibited fast convergence to the periodic solution when the simulation domain size was increase both in-plane and out-of-plane, followed by calculation of properties from the centrally located unit cell within the domain.