Mechanical behavior of woven CMCs under non-uniform stress and strain fields

Abstract

Woven ceramic matrix composites (CMCs) hot-section components will sustain spatially non-uniform stress and temperature fields in service, and the mechanical response in CMCs under inhomogeneous stress and strain fields remains indistinct. This study focuses on one noteworthy aspect of this issue: the effects of weave architecture on the mechanical response of CMCs under off-axis and thermomechanical loading. To this end, the stress and strain evolution of wavy tows in CMCs are investigated by establishing a meso-scale finite element model, which reflects the real weave architecture. Besides, the model is verified by comparing the predicted results with the experimental results of a representative woven CMC. The strain and stress concentrations appear at the location of tow cross-overs because of the bending and straightening of tows, resulting in the woven composites strength may be inferior to that of laminate composites. Although the scope of this work is limited to one type of weaving, it is expected that the modeling method can be useful in examining other types of weaving.