| Abstract Scope |
A longstanding goal of microstructural simulation is to reproduce experimentally observed outcomes in 4D (space and time). Disagreement between experiment and simulation has generally been attributed to shortcomings in the computational instantiation; however, even after several decades of improving the physical bases of computational models, a perfect match has not been achieved. In this study, we examine the sources of uncertainty in simulation and experiment using polycrystalline grain growth as an exemplar. In nominally identical molecular dynamics simulations, growth trajectories of individual grains can vary significantly due to discrete events that have cascading effects on the microstructural ensemble. Thus, microstructural events are surprisingly sensitive to atomic scale processes, which imparts an innate uncertainty in 4D simulations. While this prevents prediction of an individual grain trajectory, a range of possible trajectories can be determined for each grain; this offers a more robust, statistically-based way to compare simulation and experiment. |