Analysis of Woven and Braided Fabric-Reinforced Composites

A general purpose micromechanics analysis that discretely models the yarn architecture within the textile repeating unit cell was developed to predict overall, three-dimensional, thermal, and mechanical properties. This analytical technique was implemented in a user-friendly, personal computer-based, windows-compatible code called Textile Composite Analysis for Design (TEXCAD). TEXCAD was used to analyze plain, 5-harness satin, and 8-harness satin weave composites along with two-dimensional (2-D) braided and 2 x 2, 2-D triaxial braided composites. The calculated overall stiffnesses correlated well with available three-dimensional (3-D) finite element results and test data for both the woven and the braided composites. Parametric studies were performed to investigate the effects of yarn size on the yarn crimp and the overall thermal and mechanical constants for plain weave composites. The effects of braid angle were investigated for the 2-D braided composites. Finally, the effects of fiber volume fraction on the yarn undulations and the thermal and mechanical properties of 2 × 2, 2-D triaxial braided composites were also investigated.