A Multi-Scale Numerical Method for the Study of Size-Scale Effects in Ductile Fracture

Metals

Mauro Corrado²  Marco Paggi¹ 

[1] IMT Institute for Advanced Studies Lucca, Piazza San Francesco 19, 55100 Lucca, Italy; E-Mail:;Politecnico di Torino, Department of Structural, Geotechnical and Building Engineering, Corso Duca degli Abruzzi 24, 10129 Torino, Italy; E-Mail:

关键词: cohesive zone model;    plasticity;    finite element method;    limit analysis;    ductile fracture;    polycrystalline materials;   

DOI  :  10.3390/met4030428

来源: mdpi

【 摘 要 】

The use of a stress-strain constitutive relation for the undamaged material and a traction-separation cohesive crack model with softening for cracking has been demonstrated to be an effective strategy to predict and explain the size-scale effects on the mechanical response of quasi-brittle materials. In metals, where ductile fracture takes place, the situation is more complex due to the interplay between plasticity and fracture. In the present study, we propose a multi-scale numerical method where the shape of a global constitutive relation used at the macro-scale, the so-called hardening cohesive zone model, can be deduced from meso-scale numerical simulations of polycrystalline metals in tension. The shape of this constitutive relation, characterized by an almost linear initial branch followed by a plastic plateau with hardening and finally by softening, is in fact the result of the interplay between two basic forms of nonlinearities: elasto-plasticity inside the grains and classic cohesive cracking for the grain boundaries.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.