<POROUS_CRITERION> gurson#

Description#

This criterion was proposed by Gurson and is no doubt a widely accepted model. The model was developed to capture the progressive microrupture through void nucleation and growth. Since then it has been modified in various forms for implementation in a variety of fields, ductile rupture of metals being the most applied one. The model defines the criterion as:

\[\frac{3J_2}{\sigma_\star^2} + 2f^\star q_1 {\rm ch} \left( \frac{q_2 I_1}{2\sigma_\star}\right) -(1+q_1^2f^{\star2})\]

where \(f^\star\), \(q_1\) \(q_2\) are coefficients of the model. Names for these coefficients are fs, q1 and q2. The coefficients \(q_1\) and \(q_2\) have units of stress.

Syntax#

*porous_criterion gurson \(~\,\) coefficients \(~\,\)

prefix

size

description

default

eto

T-2

total strain

yes

sig

T-2

Cauchy stress

yes

Example#

A simple example from a test case is given below

*porous_criterion gurson
 q1 1.5
 q2 1.0
 fs = ft