Propagating material instabilities in planar architectured materials

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:202

Article

Viard, Antoine-Emmanuel^1,2  Dirrenberger, Justin¹  Forest, Samuel² 

[1] Cnam, Lab PIMM Arts & Metiers, CNRS, Paris, France

[2] PSL Univ, Ctr Mat CMAT, MINES ParisTech, CNRS UMR 7633, F-91003 Evry, France

关键词: Piobert-Luders instabilities;    Architectured materials;    Computational mechanics;    Experimental testing;    Finite element analysis;    Elastoplasticity;   

DOI  :  10.1016/j.ijsolstr.2020.05.027

来源: Elsevier

【 摘 要 】

Under tension low carbon steel exhibits inhomogeneous plastic deformation. This instability called Piobert-Luders banding creates fronts of localized strain that propagate in the structure. To date, Luders banding has been studied experimentally and numerically only in simple geometries like sheets, tubes and normalized fracture mechanics specimens. This paper focuses on architectured materials and specifically lattice structures which can be defined as a tessellation of unit-cells periodically distributed in space. This class of advanced materials draws new mechanical properties from its inner architecture. We investigate the effect of the architecture on the global behavior of the structure. Especially, how bands interact with the lattice and how to control initiation and propagation of localized strain using the architecture. An elastoplastic material model is used in order to simulate the Piobert-Luders band formation and propagation. The model also considers a large deformation framework for elastoplasticity with periodic boundary conditions in order to represent the architectured material. Initiation and propagation of material instabilities depend on the geometry as well as its on the relative orientation with respect to the loading direction. Propagating and non-propagating behaviors are identified for the Piobert-Luders bands and related to the different types of geometry. Material instabilities affect the mechanical behavior of the structure as far as they are governed by the architecture. These conclusions are compared to experimental results from tensile tests on laser-architectured specimens made of ARMCO steel. (C) 2020 Elsevier Ltd. All rights reserved.

【 授权许可】

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