From the yarn to the bulk - A meso-macro approach of the mechanical behaviour of 2D ceramic matrix composites

Two-dimensional SiC/C/SiC materials with two different fiber contents were tested at room temperature. Different scales were investigated: the yarn, the single layer of woven impregnated fabric, and the bulk 2D material made from piled-up layers. Tensile experiments associated with AE allowed the main characteristics of the mechanical behavior of the materials to be determined. The behavior of the yarn was modeled using a bilinear law, the knee corresponding to the start of damage by matrix multicracking. The damage threshold stress and the strength of the yarns were shown to be randomly distributed. Using certain assumptions concerning the yarns perpendicular to the applied stress, the behavior of single layers of fabric was predicted and compared with experiments. The mechanical behavior of the bulk 2D material was simulated from that of single layers and also compared with experimental tensile results. (Author)