POROUS_CRITERION#
Description#
This behavior object is used to enter the citerion for a porous plastic material. The description of these models will use the following notation:
CODE |
DESCRIPTION |
|---|---|
\(\ten \sigma\) |
stress tensor |
\(\ten s\) |
deviatoric stress tensor |
\(J_2\) |
the second invariant of deviatoric stress \(\frac{1}{2}\ten s:\ten s\) |
\(I_1\) |
first invariant of stress \(\trace{\ten\sigma}\) |
\(\sigma_\star\) |
current flow stress |
Syntax#
The syntax for a porous criterion requires that a type be given, followed by whatever coefficients are allowed for the particular model. As in all of Z-mat, these coefficients are entirely context sensitive.
*porous_criterion type
\(~\,~\,\) coefs
The available list of porous plastic models are summarized below.
CODE |
DESCRIPTION |
|---|---|
|
model to capture progressive microrupture |
|
generalization of the elliptic criterion for general anisotropy. |
|
criterion for densification of material |
|
elliptic criterion for compaction of fibers in a powder matrix. |
|
NIOT |
|
NIOT |
|
thermodynamic criterion through free energy |
|
criterion to study the porosity of clay |
|
NIOT |
The following pages discuss these models in details.