Tensile properties and failure analysis of 2D-C/SiC composite laminates with circular holes

Tensile properties and failure modes of the φ4 mm and φ6 mm open-hole specimens of a 2D-C/SiC composite under tensile loading were investigated. The influence of notch size on the open-hole specimen's tensile strength was analyzed by comparing with standard specimen's experimental results. Compared with the standard specimen, the tensile strength values of φ4 mm and φ6 mm open-hole specimens decrease by 1.0% and 6.6% separately. By sticking strain gauges at different locations of the open-hole specimen, the strain variation in the narrowest net section was obtained during the tensile test, and the strain concentration effect was also clearly expressed. Meanwhile, by finite element analysis (FEA), the strain distribution in the open-hole specimen was simulated. The FEA results have good consistence with experimental data. By Acoustic Emission (AE) measurement, the damage evolution of the notched specimen was derived. The AE parameters reflect the macroscopic damage process of the open-hole materials. Combined with fracture section observations, the failure behavior of the open-hole specimens was concisely discussed.