Multi-scale finite element simulation of triaxially braided composite

Braided composite is well known for its excellent through thickness properties and impact resistance. In this study, a meso-scale finite element model for studying the failure process of triaxially braided composite in presented. This model takes into account the realistic architecture, and applies periodic boundary condition along the gage section length and free boundary conditions at the two free edges of the model of the experimental coupon. Simulations of single-layer straight-sided coupon specimen under axial tension and transverse tension are conducted using this meso model and compared with experimental results. The model successfully predicts the global effective stress-strain response and local failure status. Free-edge damage is identified and found to occur periodically along the free edge and result in reduced transverse properties. A parameter study on the shear weighting factor is conducted to investigate the contribution of shear stress on the composite failure behavior, as well as, correlate with realistic test. The mechanical performance of an infinite large plate is also predicted and compared with coupon specimen results. The meso-scale infinite plate finite element model can provide data support for developing a macro-scale modeling framework.