Representative cell modeling strategy of 2.5D woven composites considering the randomness of weft cross-section for mechanical properties prediction

Abstract

In view of the large difference between the traditional unit-cell model (UCM) and the actual microstructure of 2.5D woven composites, which will affect the mechanical properties and failure behavior, a representative volume element (RVE) modeling strategy considering the randomness of weft cross-section (WFCS) is developed, and the established model is called statistical volume element (SVE) in this work. Based on the microscopy observation of warp cross-section (WPCS) and WFCS, some geometric parameters are counted, and thereby the SVE can be established. Then, the mechanical properties of 2.5D woven composites, including the stiffness and strengths in the warp and weft directions, are predicted by the SVE and UCM, respectively. Compared with the experimental results, the maximum errors predicted by the SVE and UCM are 3.84% and 15.23%, respectively. Therefore, the mechanical properties predicted by the SVE are more accurate than those predicted by the UCM. Furthermore, considering the prediction accuracy and calculation cost comprehensively, the authors suggest that the SVE and UCM should be adopted for the warp-loaded and weft-loaded progressive damage process, respectively. This work provides a method for the RVE modeling of 2.5D woven composites considering randomness, which can be extended to the modeling of other textile composites.