/FAIL/VISUAL

Block Format Keyword The purpose of this failure criteria is to record the maximum tensile 1st principal stress or maximum tensile 1st 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, visco-elastic and elasto-plastic materials.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/FAIL/VISUAL/mat_ID/unit_ID
Type C_min C_max F-coefficient F-flag   Strdef
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)

  
Type Selector type.
=0
Set to 1.
= 1 (Default)
Maximum 1st principal stress is recorded.
= 2
Maximum 1st principal strain is recorded.

(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)

 [ Pa ] or None
C_max Maximum limit for stress or strain. Values larger than this will have Damage = 1.
Note: C_max ≥ 0 .

(Real)

 [ Pa ] or None
F-coefficient Filter coefficient value. 1
If F-Flag =1, Exponential moving average,
= 0
Set to 1.
= 1 (Default)
No filtering.

(Real)

  
If F-Flag = 2, Cutoff frequency

Default = 0.0 (Real)

 [Hz]
F-flag Filter flag. 1
= 0
Set to 1.
= 1 (Default)
Exponential moving average filter.
= 2
4-Pole Butterworth filter.
  
Strdef Strain measure definition used in failure criterion.
= 1 (Default)
Strain defined by Ismstr flag in property.
= 2
Engineering strain.
= 3
True strain.

(Integer)

  
fail_ID Failure criteria identifier.

(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
                  kg                  mm                  ms
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#-  1. MATERIALS:
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/MAT/ELAST/2
steel
#              RHO_I
             7.85E-6                   0
#                  E                  nu
              210.00                  .3
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FAIL/VISUAL/2
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#     TYPE               C_MIN               C_MAX       F-COEFFICIENT    F-FLAG              Strdef
         2                 0.1                 0.8                   0         0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#enddata
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

Comments

  1. Filtering option, F-Flag:

    If F-flag=1, an exponential moving average filter is used for filtering the stress or strain. Assuming stress is being filtered.

    (1)
    σ f ( t ) = α σ ( t ) + ( 1 − α ) σ ( t − Δ t ) MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeq4Wdm3aaS baaSqaaiaadAgaaeqaaOWaaeWaaeaacaWG0baacaGLOaGaayzkaaGa eyypa0JaeqySdeMaeq4Wdm3aaeWaaeaacaWG0baacaGLOaGaayzkaa Gaey4kaSYaaeWaaeaacaaIXaGaeyOeI0IaeqySdegacaGLOaGaayzk aaGaeq4Wdm3aaeWaaeaacaWG0bGaeyOeI0IaeyiLdqKaamiDaaGaay jkaiaawMcaaaaa@4F8A@
    Where,
    σ f MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeq4Wdm3aaS baaSqaaiaadAgaaeqaaaaa@38D0@
    Filtered stress
    α MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeqySdegaaa@3795@
    The degree of weighting decrease, which is a constant smoothing factor between 0 and 1.
    A higher α MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeqySdegaaa@3795@ value discounts previous values faster, which means there is less filtering.

    If F-Flag=2, a 4-Pole-Butterworth filter is used where the F-coefficient defines the cut-off frequency. This is the same filter used in /ACCEL.

  2. Damage is output as:(2)
    D=max( 0,min[ 1, σ major −Cmin Cmax−Cmin ] ) MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiraiabg2 da9iGac2gacaGGHbGaaiiEamaabmaabaGaaGimaiaacYcaciGGTbGa aiyAaiaac6gadaWadaqaaiaaigdacaGGSaWaaSaaaeaacqaHdpWCda WgaaWcbaGaamyBaiaadggacaWGQbGaam4BaiaadkhaaeqaaOGaeyOe I0Iaam4qaiaad2gacaWGPbGaamOBaaqaaiaadoeacaWGTbGaamyyai aadIhacqGHsislcaWGdbGaamyBaiaadMgacaWGUbaaaaGaay5waiaa w2faaaGaayjkaiaawMcaaaaa@5724@

    Which means, D MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8srps0lbbf9q8WrFfeuY=Hhbbf9v8 qqaqFr0xc9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=He9 q8qqQ8frFve9Fve9Ff0dmeaacaGacmGadaWaaiqacaabaiaafaaake aacaWGebaaaa@39A0@ is always 0 ≤ D MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbwvMCKf MBHbqefqvATv2CG4uz3bIuV1wyUbqedmvETj2BSbqefm0B1jxALjhi ov2DaebbnrfifHhDYfgasaacH8srps0lbbf9q8WrFfeuY=Hhbbf9v8 qqaqFr0xc9pk0xbba9q8WqFfea0=yr0RYxir=Jbba9q8aq0=yq=He9 q8qqQ8frFve9Fve9Ff0dmeaacaGacmGadaWaaiqacaabaiaafaaake aacaWGebaaaa@39A0@ ≤ 1.

  3. Advanced math in HyperView can be used to calculate the maximum value:(3)
    σ major =D( Cmax−Cmin )+Cmin MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeq4Wdm3aaS baaSqaaiaad2gacaWGHbGaamOAaiaad+gacaWGYbaabeaakiabg2da 9iaadseadaqadaqaaiaadoeacaWGTbGaamyyaiaadIhacqGHsislca WGdbGaamyBaiaadMgacaWGUbaacaGLOaGaayzkaaGaey4kaSIaam4q aiaad2gacaWGPbGaamOBaaaa@4C9C@
  4. When maximum 1st principal strain TYPE=2 is recorded, replace stress in the previous equations with strain.
  5. For shell elements with /MAT/LAW1, only /PROP/SHELL N=1 is supported.