/FAIL/GENE1
Block Format Keyword Multiple failure models with different combinations with strain rate, thermal or mesh size dependency.
Format
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/FAIL/GENE1/mat_ID/unit_ID  
P_{min}  P_{max}  SigP1_max  Time_max  dtmin  
fct_ID_{sm}  Eps_dot_sm  Sig_max  Sigr  K  
fct_ID_{ps}  Eps_dot_ps  Eps_max  Eps_eff  Eps_vol  
Eps_min  Shear  fct_ID_{g12}  fct_ID_{g13}  fct_ID_{e1c}  
tab_ID_{fld}  Itab  Eps_dot_fld  Nstep  I_{smooth}  I_{strain}  Thinning  
Volfrac  P_thick_{fail}  NCS  T_{max}  
fct_ID_{el}  Fscale_{el}  El_ref 
(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  (Optional) Unit
identifier. (Integer, maximum 10 digits) 

P_{min}  Minimum pressure (positive in
compression). (Real) 
$\left[\text{Pa}\right]$ 
P_{max}  Maximum pressure (positive in
compression). (Real) 
$\left[\text{Pa}\right]$ 
SigP1_max  Maximum principal stress.
(Real) 
$\left[\text{Pa}\right]$ 
Time_max  Failure time. Default = 1E+20 (Real) 
$\left[\text{s}\right]$ 
dtmin  Minimum time
step. (Real) 
$\left[\text{s}\right]$ 
fct_ID_{sm}  Function identifier of the maximum
equivalent stress versus strain rate. (Integer) 

Eps_dot_sm  Reference strain rate value for
fct_ID_{sm} Default = 1 (Real) 
$\left[\frac{\text{1}}{\text{s}}\right]$ 
Sig_max  Ordinate scale factor for
fct_ID_{sm
} or maximum equivalent stress if
fct_ID_{sm}
is not defined. Default = 1, if fct_ID_{sm } is defined (Real) 
$\left[\text{Pa}\right]$ 
Sigr  Initial fracture stress for
TulerButcher criterion. (Real) 
$\left[\text{Pa}\right]$ 
K  Critical value of the damage
integral for TulerButcher criterion. (Real) 
$\left[P{a}^{2}\cdot s\right]$ 
fct_ID_{ps}  Maximum principal strain versus
strain rate function identifier. (Integer) 

Eps_dot_ps  Reference strain rate value for
fct_ID_{ps}. Default = 1 (Real) 
$\left[\frac{\text{1}}{\text{s}}\right]$ 
Eps_max  Ordinate scale factor for
fct_ID_{ps
} or maximum principal strain if
fct_ID_{ps}
is not defined. Default = 1, if fct_ID_{ps} is defined (Real) 

Eps_eff  Maximum effective
strain. (Real) 

Eps_vol  Maximum volumetric
strain. (Real) 

Eps_min  Minimum principal
strain. (Real) 

Shear  Tensorial shear strain (
$\frac{{\gamma}_{\mathrm{max}}}{2}$
). Where, ${\gamma}_{\mathrm{max}}$ is the engineering shear strain at failure. (Real) 

fct_ID_{g12}  Maximum inplane shear strain
${\gamma}_{12}$
versus element size function
identifier. (Real) 

fct_ID_{g13}  Maximum transversal shear strain
${\gamma}_{13}$
versus element size function
identifier. (Real) 

fct_ID_{e1c}  Maximum inplane major strain
${\epsilon}_{1}^{c}$
versus element size function
identifier. (Real) 

tab_ID_{fld}  Table or function identifier of the
Forming Limit Diagram. (Integer) 

Itab  Table dependency type (used only if
tab_ID_{fld}
is a table).
(Integer) 

Eps_dot_fld  Reference strain rate value for
tab_ID_{fld}. Default = 1 (Real) 
$\left[\frac{\text{1}}{\text{s}}\right]$ 
Nstep  Number of cycles for the stress
reduction. Default = 10 (Integer) 

I_{smooth}  Interpolation type (in case of
tabulated yield function).
(Integer) 

I_{strain}  Engineering / True input strain
flag.
(Integer) 

Thinning  Thinning failure
value. (Real) 

Volfrac  Damaged volume fraction to reach
before the element is deleted (fullyintegrated and higher order
solid elements only). Default = 0.5 (Real) 

P_thick_{fail}  Ratio of through thickness
integration points that must fail before the underintegrated
element is deleted. 0.0 ≤ P_thick_{fail} ≤ 1.0 Default = 1.0 (Real) 

NCS  Number of conditions to reach
before the element is deleted. Default = 1 (Integer) 

T_{max}  Maximum
temperature. (Real) 
$\left[\text{K}\right]$ 
fct_ID_{el}  Element size scale factor function
identifier for the criterias P_{min}, P_{max}, SigP1_max, Sig_max,
Sigr, K,
EpsPS_max, Eps_eff,
Eps_vol, Eps_min,
Shear,
tab_ID_{fld}
and Thinning. (Integer) 

Fscale_{el}  Element size function scale factor
for fct_ID_{el},
tab_ID_{fld}
(Itab=2),
fct_ID_{g12},
fct_ID_{g23},
fct_ID_{g13}
and
fct_ID_{e1c}. Default = 1.0 (Real) 

El_ref  Reference element size for
fct_ID_{el},
tab_ID_{fld}
(Itab=2),
fct_ID_{g12},
fct_ID_{g23},
fct_ID_{g13}
and
fct_ID_{e1c}. Default = 1.0 (Real) 
$\left[\text{m}\right]$ 
fail_ID  (Optional) Failure criteria identifier. 
Comments
 Failure criteria is used only if the value is different from 0.
 Failure models including:
 Minimum hydrostatic pressure based failure criteria:
$P\le \left{P}_{\mathrm{min}}\right$
 Maximum hydrostatic pressure based failure criteria:
$P\ge \left{P}_{\mathrm{max}}\right$
Where, hydrostatic pressure is computed as:
$P=\frac{{\sigma}_{xx}+{\sigma}_{yy}+{\sigma}_{zz}}{3}$
Note: Hydrostatic pressure is positive in compression.  Maximum principal stress:
$\sigma 1\ge \text{SigP1\_max}$ if $\text{SigP1\_max>0}$
$\sigma 1\ge \left\text{SigP1\_max}\right$ if $\text{SigP1\_max<0}$ and positive stress triaxiality value $\eta \text{=}\frac{P}{{\sigma}_{VONM}}$
 Maximum time ≥ Time_max
 Minimum elementary time step ≤ dtmin (not available with /DT/NODA option).
 Equivalent stress:
${\sigma}_{eq}\ge Sig\_max\cdot fct\_I{D}_{sm}\left(\frac{\dot{\epsilon}}{{\dot{\epsilon}}_{sm}}\right)$
 TulerButcher model:
${{\displaystyle {\int}_{0}^{t}\left[\mathrm{max}\left(0,\sigma 1Sigr\right)\right]}}^{2}dt\ge K$
Where, $\sigma 1$ is the principal stress.
 Maximum principal strain:
$\epsilon 1\ge EpsPS\_max\cdot fct\_I{D}_{ps}\left(\frac{\dot{\epsilon}}{{\dot{\epsilon}}_{ps}}\right)$
 Effective strain:
$\sqrt{\frac{2}{3}}{\epsilon}_{ij}^{\text{'}}{\epsilon}_{ij}^{\text{'}}\ge Eps\_eff$
Where, ${\epsilon}_{ij}^{\text{'}}$ is the deviatoric strain.
 Volumetric strain:
${\epsilon}_{vol}={\epsilon}_{11}+{\epsilon}_{22}+{\epsilon}_{33}\ge Eps\_vol$
 Minimum principal strain:
${\epsilon}_{3}\le \leftEps\_min\right$
 Maximum tensorial shear
strain:
${\gamma}_{1}=\frac{\left({\epsilon}_{1}{\epsilon}_{3}\right)}{2}\ge Shear$
 Mixedmode fracture criterion:
 ${\gamma}_{12}=\frac{\left({\epsilon}_{1}{\epsilon}_{2}\right)}{2}\ge fct\_I{D}_{g12}\left(\frac{Siz{e}_{el}}{El\_ref}\right)$ if $2\le \left(\frac{{\epsilon}_{2}}{{\epsilon}_{1}}\right)\le 0.5$
 ${\gamma}_{13}=\frac{\left({\epsilon}_{1}{\epsilon}_{3}\right)}{2}\ge fct\_I{D}_{g13}\left(\frac{Siz{e}_{el}}{El\_ref}\right)$ if $0.5\le \left(\frac{{\epsilon}_{2}}{{\epsilon}_{1}}\right)\le 1$

${\epsilon}_{1}\ge fct\_I{D}_{e1c}\left(\frac{Siz{e}_{el}}{El\_ref}\right)$
if
$0.5\le \left(\frac{{\epsilon}_{2}}{{\epsilon}_{1}}\right)\le 1$
Where,
 ${\epsilon}_{1}$ and ${\epsilon}_{2}$
 Inplane major and minor strains
 ${\epsilon}_{3}$
 Through thickness strain
 $Siz{e}_{el}$
 Characteristic element size
 Forming Limit Diagram (FLD):
 If Itab=1: $({\epsilon}_{1},{\epsilon}_{2})\ge Tab\_I{D}_{fld}(\frac{\dot{\epsilon}}{Eps\_dot\_fld})$
 If Itab=2:
$({\epsilon}_{1},{\epsilon}_{2})\ge Tab\_I{D}_{fld}(\frac{Siz{e}_{el}}{El\_ref})$
Where,
 ${\epsilon}_{1}$ and ${\epsilon}_{2}$
 Inplane major and minor strains
 $Siz{e}_{el}$
 Characteristic element size
 The stresses are reduced during Nstep cycles before the element deletion
 Minimum thinning based criterion:
 if Thinning > 0, shell element is deleted, if the thickness integration point thinning ≤ Thinning,
 if Thinning < 0, shell element is deleted, if the average thickness thinning ≤ Thinning.
 For solids, element is deleted, if ${\epsilon}_{zz}$ ≤ Thinning.
 Maximum element temperature ≥ Tmax
 Minimum hydrostatic pressure based failure criteria:
 Volfrac is used for fullyintegrated and higher order solids elements only. It represents the damaged volume fraction (for example, the sum of damaged integration points of associated volumes) value to reach to trigger the element deletion.
 For underintegrated linear shell elements, deletion is based on the value of P_thick_{fail}. If P_thick_{fail} > 0, the element fails and is deleted when the ratio of through thickness failed integration points equals or exceeds P_thick_{fail}. P_thick_{fail} defined in the failure model overwrite the value defined in the shell property.
 The integration point failure begins when NCS conditions are reached. Then the stresses in the integration points are reduced to zero in Nstep cycles.
 Element size dependency using the following factors:$$facto{r}_{el}=Fscal{e}_{el}\cdot fct\_I{D}_{el}\left(\frac{Siz{e}_{el}}{El\_ref}\right)$$
Where, $Siz{e}_{el}$ is the characteristic element size.
 For postprocessing results
in ANIM of H3D files, you can use the variable field
DAMA. For /FAIL/GENE1, the damage
variable is computed with the following ratio.$$D=\frac{Ncrit}{NCS}$$Where,
 $Ncrit$
 Number of specified criteria reached by the integration point.
 $NCS$
 Number of criteria to reach to trigger integration point failure.