Uncertainty propagation in reduced order models based on crystal plasticity

Abstract

In this work, an uncertainty propagation study is performed based on simulated ensembles of statistical volume elements (SVE) used to inform a reduced order internal state variable model, focusing on model form and uncertainties in numerical simulations. A rate-dependent polycrystal plasticity finite element model (CP-FEM) of cartridge brass is calibrated to room-temperature uniaxial tension testing data of an annealed sample. Model forms are considered with and without the inclusion of back stress in the CP model. Three sizes of SVE are explored for simulation uncertainty effects. Effects are explored with regard to the parameters of a Bammann–Chiesa–Johnson (BCJ) macroscopic viscoplasticity model, calibrated element-wise to SVEs from an ensemble modeled using CP-FEM simulations exploring quasi-static uniaxial tension. Variability in stress–strain response at multiple defined length-scales is measured. The selection of model form is discussed. The numerical simulation uncertainty of the model reduction process is quantified.