Simulation of Mechanical Behaviors of Ceramic Composites Under Stress-Oxidation Environment While Considering the Effect
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Simulation of Mechanical Behaviors of Ceramic Composites Under Stress-Oxidation Environment While Considering the Effect of Matrix Cracks Zhigang Sun 1 & Hongyan Shao 1 & Xuming Niu 1 & Yingdong Song 1
Received: 6 September 2015 / Accepted: 10 December 2015 # Springer Science+Business Media Dordrecht 2016
Abstract This article proposes a model which takes the effect of matrix cracking into consideration and analyzes the mechanical behaviors of unidirectional ceramic matrix composites under stress-oxidation environment. The change in the rules of mass loss ratio, residual modulus and residual strength of unidirectional C/SiC composite under different stress, oxidation time, temperature and fiber volume fraction with the temperature varying from 400 to 900 °C have been discussed in this paper. The comparison between the predicted residual mechanics properties and the experiment results demonstrates that the predicted results have a good agreement with the experiment results, which means that the model is feasible to simulate mechanical behaviors of unidirectional C/SiC composite under stress oxidation environment. Keywords Unidirectional C/SiC . Under stress-oxidation environment . Matrix cracks . Mechanical behaviors
1 Introduction As an ideal material for high-temperature components of aircraft engine, ceramic composite is anticipated to bear high-temperature, high stress environments for extended time frames, which weakens the material properties [1, 2]. For the purpose of investigation, oxidation and stress are the typically studied environmental factors. In order to
* Zhigang Sun [email protected] 1
Jiangsu Province Key Laboratory of Aerospace Power System and College of Energy and Power Engineering, Nanjing University of Aeronautics and Astronautics Nanjing, Nanjing, People’s Republic of China 210016
Appl Compos Mater
guarantee the reliability of ceramic composite structures, it is important to study the change in the mechanical behaviors of ceramic composites under stress-oxidation condition. Many studies on matrix cracking show that [3–5] when the stress induced upon a brittle matrix exceeds the initial matrix cracking stress, failure occurs in matrix. This kind of failure refers to ‘crack sources’, and it will probably develop into cracks as the stress increasing gradually. When no more matrix cracking occurs with the increasing load, the matrix cracks are saturated. The discreteness of matrix strength, the length of sample, the volume faction of fiber and so on have important effects on the matrix cracking process. Different interface strengths induce different failure mode. For low interface strengths, interface debonding occurs. For intermediate interface strengths, debonding does not occur and delay debonding; For high interface strengths, debonding does not occur and deformation is controlled by a matrix shear, with strain hardening playing an important role [6]. Ji FS et al. [7] calculated the strain energy release rates associated with the matrix crack and the interface debond, and assessed
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