Damage-Tolerant Micro-Trusses inspired from Crystal Plasticity analogues – MIRACLES

The objective of this pathfinder and interdisciplinary MIRACLES project is to draw on the knowledge inferred from bi-crystalline plasticity in face-centered cubic metals (bi-crystallography, slip/grain boundary interactions) in order to guide by geometrical analogues the manufacturing of new tailored bi- or oligo-crystalline microtrusses with disoriented meta-grains having different strut connectivities at the interface between meta-grains. Numerical simulations performed with Finite Elements (FE) for microtrusses, and analytical/ numerical fast Fourier transform (FFT) for advanced bi-crystal/ oligo-crystal plasticity respectively, will be guided with artificial intelligence (AI) methods, to propose analogues and conceptual transfers between both disciplines. Thanks to these analogues, the idea is to make emerge new tailored structures of microtrusses in terms of damage tolerance able to delay or eliminate the occurrence and the propagation of shear bands responsible for the global collapse of the structure. It is expected that these new architected bi-crystalline and oligo-crystalline microtrusses allow a better energy absorption capacity than single lattice structures. The bi- and oligo-crystalline microtrusses will be obtained by additive manufacturing process of a 316L steel based on powder bed fusion. Compressive tests with 2D and 3D image correlation during deformation will be conducted in order to quantify strain localization and validate the scientific approach. The project will result in the proposition of damage-tolerant microtrusses regarding energy absorption.