On the sensitivity of the Mohr-Coulomb ductile fracture criterion in the mixed stress-strain space on varying hardening curve approximations

5th International Conference Recent Trends in Structural Materials

Komischke, T.^1 ; Hora, P.^1

ETH Zürich, Institute of Virtual Manufacturing, Tannenstrasse 3, Zürich

8092, Switzerland^1

关键词: Ductile fracture criterion;    Fracture criteria;    Fracture model;    Fracture prediction;    Hardening curves;    Large strains;    Mohr-Coulomb;    Stress strain;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/461/1/012041/pdf
DOI  :  10.1088/1757-899X/461/1/012041

来源: IOP

【 摘 要 】

In recent years the use of the Mohr-Coulomb type fracture criteria has become popular in ductile fracture prediction. In ductile fracture prediction, fracture criteria are often transformed into the mixed stress strain space formulation and applied to numerical simulations in this formulation. This paper will investigate the shape of the Mohr Coulomb fracture criterion in the mixed stress strain space as a function of the used hardening curve formulation, in particular the hardening curve exponent n that determines the slope of the hardening curve approximation for large strains. It is found that the shape of the fracture criterion significantly depends on the slope of the hardening curve. This makes a correct extrapolation of the hardening curve for large strain values essential for a correct ductile fracture prediction using the Mohr-Coulomb fracture model in its mixed stress strain space formulation.