A damage-induced short-circuit diffusion model applied to the oxidation calculation of ceramic matrix composites (CMCs). (December 2019)

• Record Type: Journal Article
• Authors: Zhao, Yunong; Chen, Yanfei; He, Chunwang; Ai, Shigang; Fang, Daining
• Is Part Of: Composites. Volume 127(2019)
• Publication Date: 2019-12
• Subjects: Oxidation model -- Short-circuit diffusion -- Damage -- C/SiC composites; Composite materials -- Periodicals; Manufacturing processes -- Periodicals; Composite materials; Manufacturing processes; Periodicals; 620.11805
• DOI: 10.1016/j.compositesa.2019.105621
• Languages: English
• ISSNs: 1359-835X

Abstract

Abstract: In this paper, a chemo-thermal-mechanical coupled constitutive model is proposed for CMCs in an oxidizing environment. For ceramic matrix, the initiation and evolution of micro-cracks are described by a damage constitutive model. The diffusion coefficient of O2 molecules in the ceramic matrix is modelled as a function of the damage factor based on the simplifying assumption for the actual physical processes. For reinforcement materials, the oxidation reaction is taken into account, and an oxidation degree-dependent orthotropic constitutive model is adopted. Furthermore, the corresponding finite element calculation procedure is developed based on the Galerkin method and the Newton-Raphson iteration scheme. Then, as examples, the coupled failure problems of a SiC-coated C fibre monofilament and a representative volume cell (RVC) of C/SiC composites, and the oxidation process of C/SiC specimens, are studied in depth.