Prediction of the effective coefficient of thermal expansion of heterogeneous media using two-point correlation functions

Statistical continuum mechanics is used to predict the coefficient of thermal expansion (CTE) for solid oxide fuel cell glass-ceramic seal materials with different morphology and crystallinity. Two-point correlation functions are utilized to represent the heterogeneous microstructure morphology and phase distribution. The model uses two-point correlation functions in conjunction with local properties to predict the effective CTE. Prediction results are comparable to experimental CTE results. The advantage of using the statistical continuum mechanics model in predicting the effective properties of anisotropic media is shown, using the ability to take the microstructure into consideration.

Research highlights▶ In this study, a statistical continuum mechanics model is developed to predict overall coefficient of thermal expansion for glass-ceramic SOFC seals. ▶ The model developed uses two-point correlation functions to represent microstructure. ▶ The model we developed is sensitive to anisotropy in the microstructure. ▶ We find that the results fall within upper and lower bounds and are accurate to measured coefficient of thermal expansion.