/FAIL/VISUAL
Block Format Keyword The purpose of this failure criteria is to record the maximum tensile 1^{st} principal stress or maximum tensile 1^{st} principal strain in a simulation. The maximum value of all the cycles in a simulation is used to compute the damage output.
The failure model is only for visualization and does not cause element failure. It is compatible with shells and solids elements and can be used with elastic, viscoelastic and elastoplastic materials.
Format
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/FAIL/VISUAL/mat_ID/unit_ID  
Type  C_min  C_max  Fcoefficient  Fflag  Strdef 
(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) 

Type  Selector type.
(Integer) 

C_min  Lower limit for stress or strain that defines
when the maximum value starts to be recorded.
Below this value Damage = 0.
Note: C_min ≥
0. Default = 0.0 (Real) 
$\left[\text{Pa}\right]$ or None 
C_max  Maximum limit for stress or strain. Values larger
than this will have Damage =
1. Note: C_max ≥
0. (Real) 
$\left[\text{Pa}\right]$ or None 
Fcoefficient  Filter coefficient value. 1 If
FFlag =1,
Exponential moving average.
(Real) 

If
FFlag = 2,
Cutoff frequency. Default = 0.0 (Real) 
$\text{[Hz]}$  
Fflag  Filter flag. 1


Strdef  Strain measure definition used in failure criterion.
(Integer) 

fail_ID  Failure criteria
identifier. (Integer, maximum 10 digits) 
Example (Steel)
#RADIOSS STARTER
#12345678910
/UNIT/1
unit for mat
# MUNIT LUNIT TUNIT
kg mm ms
#12345678910
# 1. MATERIALS:
#12345678910
/MAT/ELAST/2
steel
# RHO_I
7.85E6 0
# E nu
210.00 .3
#12345678910
/FAIL/VISUAL/2
#12345678910
# TYPE C_MIN C_MAX FCOEFFICIENT FFLAG Strdef
2 0.1 0.8 0 0
#12345678910
#enddata
#12345678910
Comments
 Filtering
option, FFlag:
If Fflag=1, an exponential moving average filter is used for filtering the stress or strain. Assuming stress is being filtered.
$${\sigma}_{f}\left(t\right)=\alpha \sigma \left(t\right)+\left(1\alpha \right)\sigma \left(t\text{\Delta}t\right)$$Where, ${\sigma}_{f}$
 Filtered stress
 $\alpha $
 The degree of weighting decrease, which is a constant smoothing factor between 0 and 1.
If FFlag=2, a 4PoleButterworth filter is used where the Fcoefficient defines the cutoff frequency. This is the same filter used in /ACCEL.
 Damage is
output as:$$D=\mathrm{max}\left(0,\mathrm{min}\left[1,\frac{{\sigma}_{major}Cmin}{CmaxCmin}\right]\right)$$
Which means, $D$ is always 0 ≤ $D$ ≤ 1.
 Advanced math
in HyperView can be used to
calculate the maximum value:$${\sigma}_{major}=D\left(CmaxCmin\right)+Cmin$$
 When maximum 1^{st} principal strain TYPE=2 is recorded, replace stress in the previous equations with strain.
 For shell elements with /MAT/LAW1, only /PROP/SHELL N=1 is supported.