On the crushing response of random open-cell foams

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:49

Article

Gaitanaros, Stavros¹  Kyriakides, Stelios¹  Kraynik, Andrew M.² 

[1] Univ Texas Austin, Res Ctr Mech Solids Struct & Mat, Austin, TX 78712 USA

[2] Univ Manchester, CEAS, Manchester M13 9PL, Lancs, England

关键词: Open-cell foams;    Random microstructure;    Crushing response;    Numerical modeling;   

DOI  :  10.1016/j.ijsolstr.2012.03.003

来源: Elsevier

【 摘 要 】

This study examines the effect of randomness of the cellular microstructure on the calculated compressive response of a class of open-cell aluminum alloy foams. The foams are modeled using realistic random soap froth with N-3 cells generated using the Surface Evolver software. The ligaments are made straight but with non-uniform cross sectional area distributions that mimic those of the physical foams. The models are also assigned the density and anisotropy measured. The ligaments are modeled as shear deformable beams with the elasto-plastic material behavior of the Al-alloy. The microstructure is discretized with finite elements using LS-DYNA, which allows for beam-to-beam contact on the outer surface of the ligaments. 103 cell domains compressed between rigid planes are shown to reproduce the measured compressive responses in both the rise and transverse directions. This includes the complete response from the initial elastic regime, through yielding, the extended stress plateau, to densification. More importantly, localized bands of crushed cells that develop and gradually spread throughout the domain resemble closely experimental observations made using X-ray tomography. This is a major improvement over previous models that idealized monodispersed foams as periodic Kelvin cells, and should allow modeling of polydisperse foams. The contact algorithm, friction between ligaments, and generally the discretization play crucial roles in the accuracy of the calculation as well as their numerical stability. (C) 2012 Elsevier Ltd. All rights reserved.

【 授权许可】

Free