Analysis of Geometrical Parameters using a CAD System for a 3-D Braided Preform

Abstract

To estimate the precise mechanical properties of the three-dimensional (3-D) braided composite, a geometric study of a 3-D braided preform was performed. Describing yarn paths using third-order spline curves, which are close to the real pathway of the 3-D braided structure, the unit cells and the representative volume elements were determined. Finally, the CAD system for the 3-D circular braided preform was developed following these modeling sequences and applied to the parametric study of the preforms. A parametric study was conducted on the important geometric factors such as yarn retraction factor, yarn orientation angle, and yarn volume fraction and the theoretical maximum yarn volume fraction was determined. Using the developed CAD system, the relationships between processing variables and geometric parameters have been established.