Uncertainty analysis and B-basis value of tensile strength of 2D SiC/SiC composite

In this study, work on modelling uncertainty in the tensile properties of two-dimensional plain woven silicon carbide fibre-reinforced silicon carbide matrix (2D SiC/SiC) composite and B-basis values of tensile strength was carried out in the following four aspects. First, the uncertainty law and formation mechanism of the tensile properties of 2D SiC/SiC composites were researched through microstructural analysis. Subsequently, three distribution function models were established for the tensile properties of 2D SiC/SiC composites with Weibull, normal, and log-normal distribution functions. The development of three functional models was based on 30 groups of valid tensile data, linear regression methods, and Kolmogorov hypothesis testing methods. Based on the application of the model validation method, the accuracy of the three functional models was quantitatively evaluated by employing the area index of model validation. B-basis values for the tensile strength of 2D SiC/SiC composites were calculated and finally discussed for three distribution functions. The results indicate that the distribution regularity of tensile properties of 2D SiC/SiC composites could be characterized by using the three function models, and the Weibull distribution function was the most accurate. Therefore, it was preferable to calculate the B-basis values by using the Weibull distribution, with a B-basis value of 266 MPa.