Ricardo A. Lebensohn

Abstract

Fast Fourier Transform (FFT)-based modelling of strain localization in nano-metallic laminates

Crystal plasticity (CP) models allow obtaining microstructure-sensitive mechanical response of heterogeneous materials, including multiphase polycrystalline materials. CP FFT-based methods [1] are attractive due to their higher efficiency compared with CP-Finite Elements, and the direct use of use of voxelized microstructural images. In this talk, we will report recent progress on FFT-based modelling of strain localization in nano-metallic laminates (NMLs) [2] as paradigmatic case of heterostructured materials, which required combining recent FFT-based model extensions, including large strains, strain-gradient plasticity, achieving geometric accuracy from voxelized images, and non-periodic boundary conditions. We will show direct comparisons with micropillar experiments and a parametric study of the kink band formation propensity associated with different microstructural characteristics of the NMLs.

[1] Lebensohn R.A., Kanjarla A.K., P. Eisenlohr: "An elasto-viscoplastic formulation based on fast Fourier transforms for the prediction of micromechanical fields in polycrystalline materials". International Journal of Plasticity 32-33, 59-69 (2012).

[2] Zecevic M., Lebensohn R.A., Capolungo L., Non-local large-strain FFT-based formulation and its application to interface-dominated plasticity of nanometallic laminates. JMPS 173, 105187 (2023).