ePrints@IIScePrints@IISc Home | About | Browse | Latest Additions | Advanced Search | Contact | Help

Effect of microporosity on damage initiation in ceramic matrix composites

Gururaja, S and Nagaraja, A (2019) Effect of microporosity on damage initiation in ceramic matrix composites. In: ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition, GT 2019, 17 - 21 June 2019, Phoenix.

Full text not available from this repository.
Official URL: https://doi.org/10.1115/GT2019-91908


Ceramic matrix composites (CMC) are a subclass of composite materials consisting of reinforced ceramics. They retain the advantages of ceramics such as lower density and better refractory properties but exhibit better damage tolerance compared to monolithic ceramics. This combination of properties make CMCs an ideal candidate for use in high temperature sections of gas turbines. However, modeling the damage mechanisms in CMCs is complex due to the heterogeneous microstructure and the presence of processing induced defects such as matrix porosity. The effect of matrix pore location and orientation on damage initiation in CMCs is of interest in the present work. CMCs fabricated by various fabrication processes exhibit matrix pores at different length scales. Microporosities exist within fiber bundles in CMCs have a significant effect on microscale damage initiation and forms the focus of the current study. In a previous work by the authors, a two step numerical homogenization approach has been developed to model statistical distribution of matrix pores and to obtain the effective mechanical properties of CMCs in the presence of matrix porosity. A variation of that approach has been adopted to model matrix pores and investigate the severity of pores with respect to their location and orientation. CMC microstructure at the microscale has been modeled as a repeating unit cell (RUC) consisting of fiber, interphase and matrix. Ellipsoidal pores are modeled in the matrix with pore distance from the interphase-matrix interface and pore orientation with respect to the loading direction as parameters. Periodic boundary conditions (PBCs) are specified on the RUC by means of constraint equations. The effect of the pore on the local stress fields and its contribution to matrix damage is studied

Item Type: Conference Paper
Publication: Proceedings of the ASME Turbo Expo
Publisher: American Society of Mechanical Engineers (ASME)
Additional Information: The copyright for this article belongs to the American Society of Mechanical Engineers (ASME).
Keywords: Damage tolerance; Gas turbines; Microporosity; Microstructure, Different length scale; Effective mechanical properties; Heterogeneous microstructure; Monolithic ceramics; Numerical homogenization; Periodic boundary conditions; Refractory properties; Statistical distribution, Ceramic matrix composites
Department/Centre: Division of Mechanical Sciences > Aerospace Engineering(Formerly Aeronautical Engineering)
Date Deposited: 05 Dec 2022 09:24
Last Modified: 05 Dec 2022 09:24
URI: https://eprints.iisc.ac.in/id/eprint/78240

Actions (login required)

View Item View Item