Asymmetric Plasticity in Additively Manufactured 316L Stainless Steel BCC Lattice Architecture
Ignacio Ríos 1*, Seidou Abdul Herrim 2, Anne Marie Habraken 3, Anne Mertens 2, Laurent Duchêne 3, Víctor Tuninetti 1
1 Department of Mechanical Engineering, Universidad de La Frontera, Temuco 4811230, Chile; 2 Department A&M, University of Liège, 4000 Liège, Belgium; 3 Department ArGEnCo-MSM, University of Liège, 4000 Liège, Belgium
Keywords: asymmetric plasticity, laser powder bed fusion, 316L stainless steel, BCC lattice architecture, architected materials, constitutive modelling, deformation kinematics, localized instabilities
The macroscopic elastoplastic response of cellular solids is fundamentally governed by complex deformation kinematics that vary across disparate loading paths, presenting a significant challenge for the predictive modeling of architected materials. This inherent asymmetry, identified as a primary limiting factor in the predictive modeling of cellular metamaterials [1], underscores the urgent requirement for a physically based constitutive model integrated into a non-symmetric constitutive framework to establish a high-fidelity homogenized model. Uniaxial experimental characterization of 316L stainless steel body-centered cubic architectures reveals a distinct bifurcation in behavior where compressive regimes are dominated by bending-driven progressive cell collapse and stable stress plateaus, while tensile loading triggers localized plastic instabilities and premature ductility exhaustion. High-fidelity finite element simulations explicitly incorporating the lattice topology demonstrate that this non-symmetric response originates from the micromechanical distribution of stress and strain at the unit-cell level and the onset of internal structural instabilities. The demonstrated inability of conventional symmetric constitutive models to capture these effects highlights that such frameworks are physically inadequate for describing the mechanical evolution of these complex materials. Consequently, this work provides the necessary experimental and numerical evidence to support advanced homogenized frameworks capable of capturing localized strut buckling and plastic hinge formation for accurate predictions under multiaxial loading conditions.
References
- V. Tuninetti, S. Narayan, I. Ríos, B. Menacer, R. Valle, M. Al-lehaibi, M. U. Kaisan, J. Samuel, A. Oñate, G. Pincheira, A. Mertens, L. Duchêne, and C. Garrido, Biomimetic lattice structures design and manufacturing for high stress, deformation, and energy absorption performance, Biomimetics, 10(7):458, 2025, https://doi.org/10.3390/biomimetics10070458.
- X. Lijun, L. Yinan, Y. Zhu, L. Runzhi, Y. Meng, and S. Weidong, Tension-compression asymmetry in triply periodic minimal surface lattice structures, Thin-Walled Structures, 220:114351, 2026, https://doi.org/10.1016/j.tws.2025.114351.