A methodology for the estimation of the effective yield function of isotropic composites

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:87

Article

Papadioti, I.^1,2  Danas, K.³  Aravas, N.^1,4 

[1] Univ Thessaly, Dept Mech Engn, Volos 38334, Greece

[2] Ctr Res & Technol Hellas, Inst Res & Technol Thessaly I RE TE TH, Volos 38333, Greece

[3] Univ Paris Saclay, Ecole Polytech, CNRS, Mecan Solides Lab, Palaiseau, France

[4] Kyushu Univ, Int Inst Carbon Neutral Energy Res WPI 12CNER, Nishi Ku, 744 Moto Oka, Fukuoka 8190395, Japan

关键词: Homogenization;    Elasto-plasticity;    Composite materials;    Finite strains;   

DOI  :  10.1016/j.ijsolstr.2016.02.022

来源: Elsevier

【 摘 要 】

In this work we derive a general model for N phase isotropic, incompressible, rate-independent elasto-plastic materials at finite strains. The model is based on the nonlinear homogenization variational (or modified secant) method which makes use of a linear comparison composite (LCC) material to estimate the effective flow stress of the nonlinear composite material. The homogenization approach leads to an optimization problem which needs to be solved numerically for the general case of a N phase composite. In the special case of a two-phase composite an analytical result is obtained for the effective flow stress of the elasto-plastic composite material. Next, the model is validated by periodic three-dimensional unit cell calculations comprising a large number of spherical inclusions (of various sizes and of two different types) distributed randomly in a matrix phase. We find that the use of the lower Hashin-Shtrikman bound for the LCC gives the best predictions by comparison with the unit cell calculations for both the macroscopic stress-strain response as well as for the average strains in each of the phases. The formulation is subsequently extended to include hardening of the different phases. Interestingly, the model is found to be in excellent agreement even in the case where each of the phases follows a rather different hardening response. (C) 2016 Elsevier Ltd. All rights reserved.

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