<DIRECT_KINEMATIC> non_symmetric#
Description#
This kinematic hardening model provides asymmetric behavior between tension and compression as recommended for cast iron materials [M7, M8].
This model takes the tensile coefficients for computing \(\ten X_i\)
if the trace of the actual stress \(\ten 1:\ten \sigma\) is greater
than the I1_trans
value. The evolution is therefore:
where the coefficients \(C^*\) and \(D^*\) are either
\(C_t\),\(D_t\) or \(C_c\),\(D_c\) depending on the
above check on the stress. Note that in the use_x
case the evolution
is not the complete derivative where the terms involving the change
in \(C^*\) with temperature are not taken into account.
Syntax#
The basic input syntax here is:
*kinematic non_symmetric
[ I1_trans
coef-value ]
[ Ct
coef-value ]
[ Cc
coef-value ]
[ Dc
coef-value ]
[ Dc
coef-value ]
[ M
coef-value ]
[ m
coef-value ]
[ use_x
| use_alpha
]
Only one choice of use_x
or use_alpha
can be used (default is
use_x
). The default value of I1_trans
is 0. The coefficients
M
and m
are the standard Norton-like static recovery
coefficients.
Example#
The following example shows the use of this kinematic model in
combination with the cast_iron
yield criterion.
***behavior gen_evp
**elasticity isotropic
young 126000.
poisson 0.265
**potential gen_evp2 ev
*criterion cast_iron
ratio 3.
associated 1
*kinematic non_symmetric x1
I1_trans 50.
Ct 300000.0
Dt 5000.0
Cc 30000.0
Dc 500.0
*isotropic constant
R0 100.0
***return