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Computational modelling of dissipative open-cell cellular solids at finite deformations

Per Hård af Segerstad (Institutionen för tillämpad mekanik, Material- och beräkningsmekanik) ; Staffan Toll (Institutionen för tillämpad mekanik, Material- och beräkningsmekanik) ; Ragnar Larsson (Institutionen för tillämpad mekanik, Material- och beräkningsmekanik)
International Journal of Plasticity (0749-6419). Vol. 25 (2009), 5, p. 802-821.
[Artikel, refereegranskad vetenskaplig]

This study concerns the constitutive modelling of dissipative open-cell structural cellular solids under primarily finite compressive deformations and the corresponding non-linear finite element implementation. A thermodynamically consistent, mechanistic approach presented in Hard of Segerstad et al. [Hard of Segerstad, P., Larsson, R., Toll, S., 2008. A constitutive equation for open-cell cellular solids, including viscoplasticity, damage and deformation induced anisotropy. International Journal of Plasticity. 24, 896-914.] is adopted for modelling the initial linear-elastic response and the subsequent plateau behaviour. In these regions the cellular solid is considered as a network of struts, where each strut connects two vertex points. A hypothesis is proposed that the vertex points move affinely in the finite strain regime, where the struts buckle plastically. The strut deformation is further assumed to be one-dimensional and depend directly on the macroscopic deformation; thus the description of the strut response requires only a scalar valued response function. Owing to this simple ansatz, the introduction of multiple non-linear mechanisms, such as hyperelasto-viscoplasticity and damage becomes feasible for large scale computations. An additional hyperelastic volumetric response, activated near the point-of-compaction, is introduced for two reasons, (i) to capture the stiffness recovery at high compressive volumetric deformations, where the struts come into contact, and (ii) to prevent numerical instability. The model is implemented as a user defined constitutive driver in the implicit version of the finite element code ABAQUS and tested experimentally for an open-cell aluminium alloy foam (Duocel 6101-0,40 ppi). All material parameters are determined by a simple compression test, and subsequently used to simulate the indentation of a rigid sphere into a foam cylinder. The model accurately captures the experimental load-displacement relation and the deformed geometry. (C) 2008 Elsevier Ltd. All rights reserved.

Nyckelord: Cellular solids, Foams, Finite deformations, FEM, Experiments, aluminum honeycomb specimens, dominant combined loads, static crush, behavior, constitutive equation, induced anisotropy, foams, damage, plasticity, mechanisms



Denna post skapades 2010-02-23. Senast ändrad 2016-02-01.
CPL Pubid: 114178

 

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Institutioner (Chalmers)

Institutionen för tillämpad mekanik, Material- och beräkningsmekanik

Ämnesområden

Övrig teknisk mekanik

Chalmers infrastruktur