Asymptotic and uncertainty analyses of a phase field model for void formation under irradiation

We perform asymptotic analysis and uncertainty quantification of a phase field model for void formation and evolution in materials subject to irradiation. The parameters of the phase field model are obtained in terms of the underlying material specific quantities by matching the sharp interface limit of the phase field model with the corresponding sharp interface theory for void growth. To evaluate the sensitivity of phase field simulations to uncertainties in input parameters we quantify the predictions using the stochastic collocation method. Uncertainties arising from material parameters are investigated based on available experimental and atomic scale data. The results of our analysis suggest that the uncertainty in the formation and migration energies of vacancies are found to have a strong influence on the void volume fraction (or porosity). In contrast, the uncertainty resulting from the void surface energy has minimal affect. The analysis also shows that the model is consistent in the sense that its predictions do not drastically change as a result of small variations of the model input parameters. (C) 2014 Elsevier B.V. All rights reserved.