Surrogate Model-based Multiscale Analysis of Elastoplastic Composites with Nonperiodicity

Abstract

We propose a new multiscale method that combines the radial basis function (RBF)-based surrogate homogenization for elastoplastic composites and numerical material test (NMT) that allows for nonperiodic distributions of constituent materials within a representative volume element (RVE). In the offline process, we construct a constitutive database of the macroscopic stress-strain responses by conducting NMTs with a special constraint such that the volume integral of gradient of fluctuation displacement over the RVE domain is zero. Then, a surrogate model is created by using the constitutive database. In the online process, we conduct a numerical simulation of a macrostructure with the created surrogate model, followed by localization analysis using arbitrary strain histories. The validity of the proposed multiscale analysis method using RBF-based surrogate modeling is confirmed through these offline and online processes. In numerical examples, to demonstrate the modeling capability of nonperiodic microstructures, cubic and circular RVEs are targeted.