/FAIL/ORTHSTRAIN
Block Format Keyword An orthotropic strain failure criteria with size effects, strain rate effects, and damage. Available for solid and shell elements.
Format
(1)  (2)  (3)  (4)  (5)  (6)  (7)  (8)  (9)  (10) 

/FAIL/ORTHSTRAIN/mat_ID/unit_ID 
(1)  (2)  (3)  (4)  (5)  (6)  (7)  (8)  (9)  (10) 

P_thick_{fail} 
(1)  (2)  (3)  (4)  (5)  (6)  (7)  (8)  (9)  (10) 

${\dot{\epsilon}}_{0}$  F_{cut} 
(1)  (2)  (3)  (4)  (5)  (6)  (7)  (8)  (9)  (10) 

fct_ID_{el}  Fscale_{el}  El_ref 
(1)  (2)  (3)  (4)  (5)  (6)  (7)  (8)  (9)  (10) 

${\epsilon}_{11d\_t}$  ${\epsilon}_{11f\_t}$  fct_ID_{11t}  ${\epsilon}_{11d\_c}$  ${\epsilon}_{11f\_c}$  fct_ID_{11c} 
(1)  (2)  (3)  (4)  (5)  (6)  (7)  (8)  (9)  (10) 

${\epsilon}_{22d\_t}$  ${\epsilon}_{22f\_t}$  fct_ID_{22t}  ${\epsilon}_{22d\_c}$  ${\epsilon}_{22f\_c}$  fct_ID_{22c} 
(1)  (2)  (3)  (4)  (5)  (6)  (7)  (8)  (9)  (10) 

${\epsilon}_{33d\_t}$  ${\epsilon}_{33f\_t}$  fct_ID_{33t}  ${\epsilon}_{33d\_c}$  ${\epsilon}_{33f\_c}$  fct_ID_{33c} 
(1)  (2)  (3)  (4)  (5)  (6)  (7)  (8)  (9)  (10) 

${\epsilon}_{12d\_t}$  ${\epsilon}_{12f\_t}$  fct_ID_{12t}  ${\epsilon}_{12d\_c}$  ${\epsilon}_{12f\_c}$  fct_ID_{12c} 
(1)  (2)  (3)  (4)  (5)  (6)  (7)  (8)  (9)  (10) 

${\epsilon}_{23d\_t}$  ${\epsilon}_{23f\_t}$  fct_ID_{23t}  ${\epsilon}_{23d\_c}$  ${\epsilon}_{23f\_c}$  fct_ID_{23c} 
(1)  (2)  (3)  (4)  (5)  (6)  (7)  (8)  (9)  (10) 

${\epsilon}_{31d\_t}$  ${\epsilon}_{31f\_t}$  fct_ID_{31t}  ${\epsilon}_{31d\_c}$  ${\epsilon}_{31f\_c}$  fct_ID_{31c} 
(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) 

P_thick_{fail}  Percentage of through
thickness integration points that must fail before the element is
deleted (shells only). Default = 1.0 (Real) 

${\dot{\epsilon}}_{0}$  Reference strain
rate. If $\dot{\epsilon}\le {\dot{\epsilon}}_{0}$ , no strain rate effect. (Real) 
$\left[\frac{\text{1}}{\text{s}}\right]$ 
F_{cut}  Cutoff frequency for
strain rate smoothing. Default = 10^{30} (Real) 
$\text{[Hz]}$ 
fct_ID_{el}  Element size factor
function identifier. (Integer) 

Fscale_{el}  Element size function
scale factor. Default = 1.0 (Real) 

El_ref  Reference element
size. Default = 1.0 (Real) 
$\left[\text{m}\right]$ 
${\epsilon}_{11d\_t}$  Tensile strain when damage begins in direction 11.  
${\epsilon}_{11f\_t}$  Tensile strain when the material fails in direction 11.  
fct_ID_{11t}  Strain rate factor function in tension, direction 11.  
${\epsilon}_{11d\_c}$  Compression strain when damage begins in direction 11.  
${\epsilon}_{11f\_c}$  Compression strain when the material fails in direction 11.  
fct_ID_{11c}  Strain rate factor function in compression direction 11.  
${\epsilon}_{22d\_t}$  Tensile strain when damage begins in direction 22.  
${\epsilon}_{22f\_t}$  Tensile strain when the material fails in direction 22.  
fct_ID_{22t}  Strain rate factor function in tension direction 22.  
${\epsilon}_{22d\_c}$  Compression strain when damage begins in direction 22.  
${\epsilon}_{22f\_c}$  Compression strain when the material fails in direction 22.  
fct_ID_{22c}  Strain rate factor function in compression direction 22.  
${\epsilon}_{33d\_t}$  Tensile strain when damage begins in direction 33.  
${\epsilon}_{33f\_t}$  Tensile strain when the material fails in direction 33.  
fct_ID_{33t}  Strain rate function in tension direction 33.  
${\epsilon}_{33d\_c}$  Compression strain when damage begins in direction 33.  
${\epsilon}_{33f\_c}$  Compression strain when the material fails in direction 33.  
fct_ID_{33c}  Strain rate factor function in compression direction 33.  
${\epsilon}_{12d\_t}$  Tensile strain when damage begins in direction 12.  
${\epsilon}_{12f\_t}$  Tensile strain when the material fails in direction 12.  
fct_ID_{12t}  Strain rate factor function in tension direction 12.  
${\epsilon}_{12d\_c}$  Compression strain when damage begins in direction 12.  
${\epsilon}_{12f\_c}$  Compression strain when the material fails in direction 12.  
fct_ID_{12c}  Strain rate factor function in compression direction 12.  
${\epsilon}_{23d\_t}$  Tensile strain when damage begins in direction 23.  
${\epsilon}_{23f\_t}$  Tensile strain when the material fails in direction 23.  
fct_ID_{23t}  Strain rate factor function in tension direction 23.  
${\epsilon}_{23d\_c}$  Compression strain when damage begins in direction 23.  
${\epsilon}_{23f\_c}$  Compression strain when the material fails in direction 23.  
fct_ID_{23c}  Strain rate factor function in compression direction 23.  
${\epsilon}_{31d\_t}$  Tensile strain when damage begins in direction 31.  
${\epsilon}_{31f\_t}$  Tensile strain when the material fails in direction 31.  
fct_ID_{31t}  Strain rate factor function in tension direction 31.  
${\epsilon}_{31d\_c}$  Compression strain when damage begins in direction 31.  
${\epsilon}_{31f\_c}$  Compression strain when the material fails in direction 31.  
fct_ID_{31c}  Strain rate factor function in compression direction 31.  
fail_ID  (Optional) Failure model
identifier. (Integer, maximum 10 digits) 
Example
#RADIOSS STARTER
#12345678910
/UNIT/1
unit for mat
kg mm ms
#12345678910
# 2. MATERIALS:
#12345678910
/MAT/PLAS_TAB/1/1
DP600 from SSAB Homepage
# Init. dens. Ref. dens.
7.8E6 0
# E Nu Eps_p_max Eps_t1 Eps_t2
210 .3 0 0 0
# Nfunc Fsmooth Chard Fcut Eps_f
4 1 0 10 0
# Ipfun Fpscale
0 0
# Funtions
14 14 14 14
# Scale factors
1 1.0 1.2 1.2
# Strain rates
1e6 1e5 0.1 1.0
#12345678910
/FAIL/ORTHSTRAIN/1/1
# Pthick_fail
0.8
# Epsp_ref Fcut
0.0 0.0
# fct_el Fscale_el El_ref
0 0 0
# eps11d_t eps11f_t fct_11t eps11d_c eps11f_c fct_11c
0.01 0.05 1000 0.1 0.2 2000
# eps22d_t eps22f_t fct_22t eps22d_c eps22f_c fct_22c
0.01 0.05 1001 0.1 0.2 2001
# eps33d_t eps33f_t fct_33t eps33d_c eps33f_c fct_33c
0.01 0.05 1001 0.1 0.2 2001
# eps12d_t eps12f_t fct_12t eps12d_c eps12f_c fct_12c
0.01 0.05 1001 0.1 0.2 2001
# eps23d_t eps23f_t fct_23t eps23d_c eps23f_c fct_23c
0.01 0.05 1001 0.1 0.2 2001
# eps31d_t eps31f_t fct_31t eps31d_c eps31f_c fct_31c
0.01 0.05 1001 0.1 0.2 2001
# Fail_ID
#12345678910
/FUNCT/1000
eps11t
# X Y
0. 1
1. 1
1.2 1
1.0e20 1
/FUNCT/2000
eps11c
# X Y
0. 1
.05 1
.06 1
1.0e20 1
/FUNCT/1001
bidont
# X Y
0. 1
1.0e20 1
/FUNCT/2001
bidonc
# X Y
0. 1
1.0e20 1
#12345678910
/FUNCT/14
Mat_Curev Quasistatic DOCOL DP 600 (Material from SSAB Homepage 2010)
# X Y
0 .306
.00112 .415
.00218 .445
.003 .461
.00404 .474
.00517 .489
.00613 .498
.0071 .505
.00806 .512
.00901 .522
.0102 .53
.0121 .543
.013 .55
.014 .555
.015 .561
.0159 .567
.0171 .572
.0181 .577
.0204 .592
.0303 .632
.0405 .663
.0502 .687
.06 .706
.0702 .722
.0807 .737
.09 .749
.0997 .758
.101 .759
.11 .768
.15000001 .805
.2 .84
.30000001 .9
.5 1
1 1.21
#12345678910
#ENDDATA
#12345678910
Comments
 A damage factor is the maximum over time and is
calculated for each direction and stress state via:
(1) $${d}_{ijl}=\left(\frac{{\epsilon}_{ijf\_l}}{{\epsilon}_{ijl}}\right)\left(\frac{{\epsilon}_{ijl}\alpha \cdot {\epsilon}_{ijd\_l}}{{\epsilon}_{ijf\_l}{\epsilon}_{ijd\_l}}\right)$$Where, the direction is indicated by using the common ij notation and loading state is either compression (l=c) or tension (l=t).
Where, $\alpha =facto{r}_{el}\cdot facto{r}_{rate}$ .
The element size correction factor is:(2) $$facto{r}_{el}=Fscal{e}_{el}\cdot {\mathrm{f}}_{el}\left(\frac{Siz{e}_{el}}{El\_ref}\right)$$Where, ${\mathrm{f}}_{el}$
 Element size correction factor function defined via $fct\_I{D}_{el}$
 $Siz{e}_{el}$
 Characteristic element size.
The strain rate factor is:(3) $$facto{r}_{rate}={\mathrm{f}}_{ijl}\left(\frac{{\dot{\epsilon}}_{ijl}}{{\dot{\epsilon}}_{0}}\right)$$Where, ${\mathrm{f}}_{ijl}$
 Strain rate factor function defined via $fct\_I{D}_{ijl}$ .
 ${\dot{\epsilon}}_{ijl}$
 Current (filtered) strain rate in direction ij and load case l.
 ${\dot{\epsilon}}_{0}$
 Entered reference strain rate.
 Material damage
and stress softening are calculated as:${D}_{\mathrm{max}}=\mathrm{max}\left({d}_{ijl}\right)$ and $\sigma =\left(1{D}_{\mathrm{max}}\right)\sigma $
 If $0<{D}_{\mathrm{max}}<1$ , the stress tensor is reduced.
 If ${D}_{\mathrm{max}}\ge 1$ ,the material has failed and the integration point stress tensor is set to zero.
 ${D}_{\mathrm{max}}$ can be output using options in /ANIM/Eltype/DAMA or /H3D/Eltype/DAMA.
 Solid elements are
deleted when all integration points reach the failure criterion. Shells are deleted
when the sum of thickness of failed layers /integration points in the normal
direction is greater than prescribed
P_thick_{fail}
value.
(4) $$\frac{{\displaystyle \sum _{layers}thicknes{s}_{fail}}}{{\displaystyle \sum _{layers}IP}}>P\_thic{k}_{fail}$$  When the failure model is applied to a material in STACK property, P_thick_{fail} defines a relative thickness of failed integration points, necessary to switch off the corresponding layer. The global element suppression criterion must be defined at the property level.
 /FAIL/ORTHSTRAIN should be only associated to materials compatible with orthotropic shell properties. LAW25 is compatible only if it’s used within shell property TYPE51.