Study on the Dynamic Mechanical Behavior of 2D C/SiC Composites at Medium Strain Rates

Two-dimensional C/SiC are promising candidates for use in high-temperature structures in aeroengines and thermal protection systems in the aerospace industry, which will be subjected to loads in various directions during service. In this paper, the in-plane tensile, compressive, and shear mechanical properties of 2D C/SiC were investigated over a strain-rate range of 10−5 s−1 to 10 s−1. The failure mechanisms of the material under different loading conditions were analyzed. The study reveals that 2D C/SiC exhibits nonlinear stress–strain relationships under tension and shear, while it displays a linear stress–strain relationship under compression similar to the quasi-static loading state. The strain-rate strengthening effect is most pronounced under compression, whereas the effect is less significant under tensile loading. The reason for the observed increase in strength is the additional energy consumed by multiple crack initiation and propagation. A rate-dependent constitutive model was fitted, which agrees well with the experimental data for both tensile and shear loading conditions.