In-plane mechanical behavior and failure mode of a 2D-SiC/SiC composite under uniaxial dynamic compression

Dynamic and quasi-static in-plane compression failure process of a 2D-SiC/SiC composite were explored in this paper. Specular Reflection Method (SRM) was introduced to capture the real-time high-resolution images of the SiC/SiC composite in tests. The fracture surfaces of the subject composite under dynamic and quasi-static loading show different angles with loading direction. Dynamic fracture surface results showed a larger angle with the loading direction, with fiber breakage without debonding. However, in the quasi-static tests fracture surface showed a small angle with the loading direction, with fiber debonding and fiber bundle buckling. Scanning electron microscope (SEM) characterization of fragments obtained after experiments were used to characterize the deformation mechanisms of the 2D-SiC/SiC composite. Although both shear deformation and delamination were found under quasi-static and dynamic loading, shear deformation dominated the failure process of specimens during dynamic compression. Two microscopic fracture modes were concluded from the failure process of quasi-static and dynamic loadings. The strength of the fiber-matrix interface significantly influenced the fracture modes. Finally, an effort was made to simulate the dynamic failure process of SiC/SiC composite using the topological structure of a full-size specimen.