Effect of Local Fiber Volume Fraction Variation on Stress-States in a Twill Orthogonally Woven Textile Composite

Abstract

In this paper, we developed a model for the mesoscale elastic properties for tows as a function of the fiber volume fraction and studied the effect of accounting for the variation of the local fiber ð‘‰ð‘“ in the tows on the predicted stress concentrations in each type of constituent. We used ensembles of microscale fiber/matrix analyses to develop a model of the mesoscale properties as a function of the local fiber volume fraction. We used VTMS to create a twill orthogonally woven 3D textile composite and performed two mesoscale elastic analyses: one with and one without the variation of fiber volume fraction included. In both simulations, the textile was subjected to tension along the warp direction. The results showed up to a 20% difference between the two simulations for the most severe stresses in the binders. In warps and wefts, the stress concentrations differed up to 5%, and in the matrix, the stress concentrations differed between 2% and 6%. The results showed that accounting for the variation of the local fiber volume fraction in the tows could significantly affect the predicted initiation of damage, but reliable quantitative predictions will require additional experimental data that quantify the relationship between fiber fraction and allowables.