/FAIL/WILKINS

Block Format Keyword Describes the Wilkins failure model.

Format


(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
/FAIL/WILKINS/`mat_ID`/`unit_ID`
$α$		$β$		$P_{\lim}$		$D_{f}$		`I`_{fail_sh}	`I`_{fail_so}

Optional Line


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

Definition


Field	Contents	SI Unit Example
`mat_ID`	Material identifier. (Integer, maximum 10 digits)
`unit_ID`	Unit Identifier. (Integer, maximum 10 digits)
$α$	Hydrostatic pressure exponent. (Real)
$β$	Deviatoric coefficient. (Real)
$P_{\lim}$	Hydrostatic pressure limit. (Real)	$[Pa]$
$D_{f}$	Critical damage. (Real)
`I`_{fail_sh}	Shell failure flag. = 1 Shell is deleted, if $D_{c} \geq D_{f}$ for one integration point or layer. = 2 For each integration point, the stress tensor is set to zero, if $D_{c} \geq D_{f}$ and shell is deleted, if $D_{c} \geq D_{f}$ for all integration points or layers. (Integer)
`I`_{fail_so}	Solid failure flag. = 1 Solid is deleted, if $D_{c} \geq D_{f}$ for one integration point. = 2 For each integration point, the deviatoric stress tensor vanishes, if $D_{c} \geq D_{f}$ . (Integer)
`fail_ID`	Failure criteria identifier. 2 (Integer, maximum 10 digits)

Example (Metal)

#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
Metal
#              RHO_I
              2.8E-9                   0
#                  E                  Nu
               60000                  .3
#                  a                   b                   n           EPS_p_max            SIG_max0
                 370                 190                  .4                   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/WILKINS/1/1
#              Alpha                Beta                Plim                  Df  Ifail_sh  Ifail_so
                 1.8                 .75                 750                 0.3         1         0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#enddata
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

Comments

The cumulative damage is:
$D_{c} = \int W_{1} W_{2} d {\bar{ε}}_{p}$
Where,
$W_{1} = {(\frac{1}{1 + a P})}^{α}$
$a = - \frac{1}{P_{\lim}}$
Where,

$P$

Hydro pressure

$P = - \frac{1}{3} \sum_{j = 1}^{3} σ_{j}_{j}$
$W_{2} = {(2 - A)}^{β}$
$A = \max (\frac{s_{2}}{s_{1}}, \frac{s_{2}}{s_{3}}), s_{1} \geq s_{2} \geq s_{3}$
Where, $s_{1}, s_{2}, s_{3}$ are the deviatoric stresses.
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).