2D-C/SiC复合材料面内剪切性能统计及强度B基准值

The distribution of in-plane shear modulus and strength of 2D-C/SiC composites, and its B-basis value of strength were studied by testing thirty Iosipescu specimens under shear load. The distribution and parameters about in-plane shear properties of 2D-C/SiC composites were determined by the method that liner regression combined with hypothesis testing, and the statistics results obtained by two different empirical failure probabilities were compared. The mechanism of the dispersibility of the in-plane shear strength was demonstrated by the micro-CT(μ-CT)photographs and SEM(scanning electron microscope) photographs through observation on the narrowest net cross-section. Finally, the Weibull B-basis value of the strength was calculated based on the distribution law. The results show that the strength and modulus of 2D-C/SiC composites both follow weibull, normal and lognormal distribution, and the prediction has good agreement with test data. The distribution of the mechanical properties is not affected by two empirical failure probabilities. The dispersibility of the strength is connected with the density of the narrowest net cross-section and the interface debonding length. Finally, its B-basis value of strength is 80.41MPa.