High-temperature Tensile Properties and Failure Analysis of Open-hole SiC_f/SiC Composites

The utilization of ceramic matrix composite (CMC) can significantly enhance the service temperature of the hot-end components of aero-engines and reduce the structural weight. Aiming at the engineering application requirements of SiC_f/SiC composites in aero-engine hot-end components, tensile mechanical behavior tests and precise simulation studies of SiC_f/SiC composites with open-hole were carried out. The results show that at 1350 ℃, the elastic modulus and strength properties of plain-woven SiC_f/SiC decrease markedly, with the high-temperature strength retaining approximately 70% of room temperature performance. Crucially, the central open-holes disrupt the load transfer pathways within the fiber bundle, thereby reducing overall load-bearing capacity of the specimen and causing failure and damage at the openings. There are many mesoscopic pore defects in the plain-woven SiC_f/SiC composites, which make the fiber bundle fracture relatively independent. In summary, the stress-strain distribution and damage evolution characteristics of open-hole specimen can be effectively obtained by employing the specimen-level cell model, which is an important technical approach to achieve accurate simulation of plain-woven composites.