Low Degree of Homogeneity Due to Phase Shifts for Woven Composites

In this study, variation of effective properties due to fiber tow phase shifts was investigated for woven textile composites. Plain weave unit cells were modeled with randomly selected phase shifts. Effective properties were calculated using macro finite elements and the results were assessed statistically. It was found that the effective properties depended strongly on the tow phase shifts for thin plain weave composites. The variation in the effective modulus and Poisson's ratio was large, and it showed skewed distributions. As the number of layers increased, however, the average properties converged and the coefficient of variation decreased.