/FAIL/XFEM_JOHNS (Obsolete)

Format

(1)	(3)	(5)	(7)	(9)
/FAIL/XFEM_JOHNS/`mat_ID`/`unit_ID`
`D`₁	`D`₂	`D`₃	`D`₄	`D`₅
${\dot{ε}}_{0}$	`I`_{fail_sh}

Optional Line

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
`fail_ID`

Definitions

Field	Contents	SI Unit Example
`mat_ID`	Material identifier (Integer, maximum 10 digits)
`unit_ID`	Unit Identifier (Integer, maximum 10 digits)
`D`₁	1^st parameter (Real)
`D`₂	2^nd parameter (Real)
`D`₃	3^rd parameter (Real)
`D`₄	4^th parameter (Real)
`D`₅	5^th parameter (Real)
${\dot{ε}}_{0}$	Reference strain rate (Real)	$[\frac{1}{s}]$
`I`_{fail_sh}	Shell failure flag = 1 Shell is cracked (not deleted), if $D = \sum \frac{Δ ε_{p}}{ε_{f}} \geq 1$ for one integration point or layer. = 2 For each integration point, the stress tensor is set to zero, if $D = \sum \frac{Δ ε_{p}}{ε_{f}} \geq 1$ ; and shell is cracked (not deleted), for all integration points or layers. (Integer)
`fail_ID`	(Optional) Failure criteria identifier 4 (Integer, maximum 10 digits)

Example (Steel)

#RADIOSS STARTER
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/UNIT/1
unit for mat
#              MUNIT               LUNIT               TUNIT
Mg                  mm                   s
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#-  1. MATERIALS:
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/MAT/PLAS_JOHNS/1/1
Steel
#              RHO_I
              7.8E-9
#                  E                  Nu
              210000                  .3
#                  a                   b                   n           EPS_p_max            SIG_max0
                 270                 450                  .6                   0                   0
#                  c           EPS_DOT_0       ICC   Fsmooth               F_cut               Chard
                   0                   0         0         0                   0                   0
#                  m              T_melt              rhoC_p                 T_r
                   0                   0                   0                   0
/FAIL/JOHNSON/1/1
#                 D1                  D2                  D3                  D4                  D5
                0.11                0.08                -1.5                   0                   0
#              EPS_0  Ifail_sh  Ifail_so                                    Dadv               Ixfem
                   1         1         1                                     0.5                   1
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#enddata
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

Comments

This failure model is available for Shell only.
The parameters are used in the stress-strain relationship:
(1)
$ε_{f} = [D_{1} + D_{2} \exp (D_{3} σ^{*})] [1 + D_{4} In ({\dot{ε}}^{*})] [1 + D_{5} T^{*}]$

Where,

$σ^{*} = \frac{σ_{m}}{σ_{V M}}$ ; ${\dot{ε}}^{*} = \frac{\dot{ε}}{{\dot{ε}}_{0}}$

T* is computed in the material law, if this one is thermo plastic, like /MAT/LAW4 (HYD_JCOOK).
Current known limitations are:
- /PARITH/ON does not ensure results repeatability, if SPMD > 1; it works in SMP parallel mode only.
- XFEM is currently NOT compatible with either /ANIM/VECT or with /PARITH/OFF.
The fail_ID is used with /STATE/BRICK/FAIL and /INIBRI/FAIL. There is no default value. If the line is blank, no value will be output for failure model variables in the /INIBRI/FAIL (written in .sta file with /STATE/BRICK/FAIL option).