Single Ply and Multi-Ply Braided Composite Response Predictions Using Modified Subcell Approach.

In this work, the modeling of triaxially braided composites was explored through a subcell approach using an improved semianalytical discretization scheme. The unit cell of the braided composite was divided into four unique subcells, each approximated by a mosaic stacking of unidirectional composite plies and modeled through the use of layered-shell elements within the finite-element model. Two subcell discretization schemes were investigated: a model explicitly capturing pure matrix regions, and a model which absorbed pure matrix pockets into neighboring tow plies. Differences in the mesostructure between single-ply and multi-ply braid coupons were addressed through modifications to the subcell discretization. The absorbed matrix model simulated the unique out-of-plane deformations observed experimentally in single-ply tensile tests with acceptable moduli predictions. An investigation of single-shell versus multi-shell coupons for the analysis of multi-ply braids revealed the through-thickness modeling approach was found to have a significant effect on the apparent transverse modulus. Improved moduli predictions in both the axial and transverse directions were obtained by explicitly modeling braided plies with individual layers of shell elements. [ABSTRACT FROM AUTHOR]