Multiscale simulation of spatially correlated microstructure via a latent space representation.

When deformation gradients act on the scale of the microstructure of a part due to geometry and loading, spatial correlations and finite-size effects in simulation cells cannot be neglected. We propose a multiscale method that accounts for these effects using a variational autoencoder to encode the structure–property map of the stochastic volume elements making up the statistical description of the part. In this paradigm the autoencoder can be used to directly encode the microstructure or, alternatively, its latent space can be sampled to provide likely realizations. We demonstrate the method on three examples using the common additively manufactured material AlSi 10 Mg in: (a) a comparison with direct numerical simulation of the part microstructure, (b) a push forward of microstructural uncertainty to performance quantities of interest, and (c) a simulation of functional gradation of a part with stochastic microstructure. • Focus is on multiscale simulation where spatial correlations and finite-size effects cannot be neglected. • A multiscale method with a variational autoencoder to encode the structure-property map is proposed. • The autoencoder can directly encode microstructure or its latent space can be sampled. • Demonstrations: comparison to full-scale simulation, push forward of microstructural uncertainty, simulation of functional gradation. [ABSTRACT FROM AUTHOR]