Uncertainty quantification method for mechanical behavior of C/SiC composite and its experimental validation

C/SiC composites exhibit nonlinearity and dispersions in macroscopic constitutive behaviors, and both characteristics are dependent on external load. Previously, only uncertainties in elastic modulus have been considered, and this is not sufficient. In this paper, a characterization method for uncertainty in material behavior of a C/SiC composite is established by introducing parameter uncertainties into the constitutive model. Two types of uncertainties related to material constants and functions of the constitutive model are considered and quantified with experimental data. Tolerance-interval and optimized kernel-density methods are employed to tackle sparse data condition. The method is validated against two categories of experiments: coupon tests and tension experiments for hat-shaped components. Monte-Carlo simulation and the sparse polynomial chaos expansion method are employed to propagate the uncertainties into strain responses. The predicted uncertainties of the strains agree well with the experimental results obtained, indicating the effectiveness of the method. The method could be employed easily in uncertainty quantification of structural responses, and further, could facilitate model calibration, reliability design, and other applications for which material uncertainties are significant factors.