A Coupled FE‐FFT Multiscale Framework for Heterogeneous Porous Materials Using preCICE

ABSTRACT This work presents a coupled finite element–fast Fourier transform (FE–FFT) multiscale framework for the simulation of heterogeneous and graded porous materials. The macroscopic boundary value problem is solved with the finite element (FE) method in Julia using Ferrite.jl, while the microscopic response of periodic unit cells is obtained from fast Fourier transform (FFT)‐based homogenization based on the Lippmann–Schwinger equation. The two scales are coupled at every macroscopic Gauss point through the open‐source library preCICE together with the Micro Manager, which enable a modular, language‐agnostic exchange of strain, stress, and consistent tangent without modification of the underlying solvers. A hybrid material zone concept combines fully resolved porous regions with computationally cheap local constitutive models within a single macroscopic mesh, while a per‐Gauss‐point assignment of periodic microstructures allows graded and otherwise heterogeneous microstructures to be represented naturally. Several acceleration strategies such as finite‐difference tangents, a modified Newton scheme, and MPI‐parallel microscale execution reduce the dominant cost of the microstructure solves. The framework is validated on a graded porous aluminum specimen with three layers of increasing porosity under uniaxial compression, for which the FE–FFT model reproduces the fully resolved FFT reference stress–strain response with a maximum deviation below , demonstrating accurate predictions at substantially reduced computational cost.