Parameterized unit-cell models for stiffness performance analyses of three-dimensional n-directional braided composites

Abstract

Parameterized unit-cell models of three-dimensional n-directional ( n = 5, full-5, 6, or 7) braided structures are established based on the internal structures of three-dimensional braided composites. Braiding structures are characterized by model parameters, and the relationships between fiber volume fraction and model parameters are analyzed in this study. A finite element stiffness prediction is conducted using the parameterized models, and the simulation results are found to be consistent with the experimental data. Model parameters’ influence on elastic constants of the composites is studied through finite element method. The research shows that the models can describe braiding structures precisely and are applicable to stiffness performance analyses, and provides an available approach to mesoscopic mechanical analysis and structural optimization design of three-dimensional braided composites.