2D woven C/SiC ceramic matrix composites inherently exhibit dispersion in mechanical properties, posing great challenges to their structural design and engineering applications. This dispersion primarily stems from the random distribution of voids and defects within the composite material, as well as the uneven thermochemical damage incurred during manufacturing. To address this issue, this paper proposes a probabilistic volume element model to characterize the dispersion in the mechanical properties of C/SiC composites and investigate the propagation of uncertainties and correlations across scales. To capture the typical nonlinear behavior of C/SiC composites under uniaxial tension, a progressive damage constitutive law was developed within the mesoscale finite element model based on the Linde criterion. Uncertainties in material properties were modeled by implementing Weibull and normal distributions for strength and modulus, respectively. Bivariate copula functions combined with the Bootstrap method were employed to quantify the correlation between strength and modulus, as observed in limited experimental data. Convolutional neural networks were introduced to model the propagation of uncertainty in these correlated parameters. The networks were iteratively updated through transfer learning and optimization algorithms to address the correlation inverse problem, enabling the identification of dependence between mesoscale parameters based on macroscale experimental data, with subsequent quantification using copula functions. Statistical analysis emphasizes the significance of incorporating parameter correlations in multiscale simulations for achieving accurate uncertainty quantification of mechanical properties.
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