Dynamic tensile behavior of unidirectional CVI SiCf/SiC composites with PyC interface

Abstract

Dynamic tensile experiments of unidirectional (UD) SiC${}_f$/PyC/SiC composites and SiC fiber bundles were performed using a Kolsky tension bar test system. Typical failure characteristics of UD ceramic matrix composites (CMCs), including matrix crack spacing, fiber pull-outs, matrix fracture surfaces and fiber fracture surfaces, were observed through optical and scanning electron microscopes. By combining micro-damage characteristics with mechanical behavior, we analyzed the dynamic damage mechanisms of UD-CMCs. Based on the test results, the dynamic loading effects on micro-mechanical parameters and their subsequent impact on the macro composite were determined. Finally, with these validated micro-parameters, we developed a rate-dependent constitutive model for UD-CMCs.