Multi-scale Model of Residual Strength of 2D Plain Weave C/SiC Composites in Oxidation Atmosphere
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Multi-scale Model of Residual Strength of 2D Plain Weave C/SiC Composites in Oxidation Atmosphere Xihui Chen 1 & Zhigang Sun 1 & Jianfen Sun 1 & Yingdong Song 1
Received: 1 June 2016 / Accepted: 3 June 2016 # Springer Science+Business Media Dordrecht 2016
Abstract Multi-scale models play an important role in capturing the nonlinear response of woven carbon fiber reinforced ceramic matrix composites. In plain weave carbon fiber/silicon carbon (C/SiC) composites, the carbon fibers and interphases will be oxidized at elevated temperature and the strength of the composite will be degraded when oxygen enters microcracks formed in the as-produced parts due to the mismatch in thermal properties between constituents. As a result of the oxidation on fiber surface, fiber shows a notch-like morphology. In this paper, the change rule of fiber notch depth is fitted by circular function. And a multiscale model based upon the change rule of fiber notch depth is developed to simulate the residual strength and post-oxidation stress–strain curves of the composite. The multi-scale model is able to accurately predict the residual strength and post-oxidation stress–strain curves of the composite. Besides, the simulated residual strength and post-oxidation stress–strain curves of 2D plain weave C/SiC composites in oxidation atmosphere show good agreements with experimental results. Furthermore, the oxidation time and temperature of the composite are investigated to show their influences upon the residual strength and post-oxidation stress– strain curves of plain weave C/SiC composites. Keywords 2D plain weave C/SiC composite . Multi-scale model . Oxidation . Residual strength . Post-oxidation stress–strain curves
1 Introduction The extreme stiffness, strength, and toughness, as well as their resilient behavior in harsh environments of continuous carbon fiber-reinforced silcon carbide ceramic matrix composite
* Zhigang Sun [email protected]
1
Key Laboratory of Aero-Engine Thermal Environment and Structure, Ministry of Industry and Information Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, People’s Republic of China
Appl Compos Mater
(C/SiC) make them an ideal choice over monolithic ceramics for many aerospace applications, such as hot engine components [1–4]. Of particular interest are the woven SiC-matrix-based CMCs reinforced by C fibers [5]. Most of the CMCs are reinforced with two dimensional (2D) fiber fabrics. For its low weight and high strength plain woven composite is widely used in aeronautics engineering and aerospace engineering [6], e.g., combustor liners for gas turbine engines, would be constantly loaded in high temperature oxidizing environments over hundreds even thousands of hours [7, 8]. However, one of the barriers to their uses in certain longterm or reusable applications is that degradation of the carbon fibers in oxidizing environments can lead to strength reduction and component failure [9]. Since the as-fabricated micro-cracks in the SiC matrix act as oxygen transport
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