/PROP/TYPE1 (SHELL)

Block Format Keyword Describes the shell property set which is used for 3-node or 4-node shell element. Belytschko, QBAT or QEPH shell formulation are available.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/PROP/TYPE1/prop_ID/unit_ID or /PROP/SHELL/prop_ID/unit_ID
prop_title
Ishell Ismstr Ish3n Idrill     P_thickfail    
hm hf hr dm dn
N   Thick Ashear   Ithick Iplas  

Definition

Field Contents SI Unit Example
prop_ID Property identifier.

(Integer, maximum 10 digits)

  
unit_ID Unit Identifier.

(Integer, maximum 10 digits)

  
prop_title Property title.

(Character, maximum 100 characters)

  
Ishell 4 node shell element formulation flag.
= 0
Use value in /DEF_SHELL.
= 1 Default, if /DEF_SHELL is not defined
Q4, visco-elastic hourglass modes orthogonal to deformation and rigid modes (Belytschko).
= 2
Q4, visco-elastic hourglass without orthogonality (Hallquist).
= 3
Q4, elasto-plastic hourglass with orthogonality.
= 4
Q4 with improved type 1 formulation (orthogonalization for warped elements).
= 12
QBAT shell formulation.
= 24
QEPH shell formulation.

(Integer)

  
Ismstr Shell small strain formulation flag. 4
= -1
Automatically set the best value according to element type and material law.
= 0
Use value in /DEF_SHELL.
= 1
Small strain from time = 0 (formulation compatible with all other formulation flags).
= 2 Default, if /DEF_SHELL is not defined
Full geometric nonlinearities with possible small strain formulation activation in Radioss Engine (option /DT/SHELL/CST).
= 3
Old small strain formulation (only compatible with Ishell = 2).
= 4
Full geometric nonlinearities (in Radioss Engine, option /DT/SHELL/CST has no effect).
= 10
Lagrange type total strain for hyperelastic material laws.

(Integer)

  
Ish3n 3 node shell element formulation flag.
= 0
Use value in /DEF_SHELL.
= 1
Standard triangle (C0).
= 2 Default, if /DEF_SHELL is not defined
Standard triangle (C0) with modification for large rotation.
= 30
DKT18.
= 31
DKT_S3, which based on DTK12 of BATOZ (refer to the Element Library in the Theory Manual).

(Integer)

  
Idrill Drilling degree of freedom stiffness flag. 3
= 0
Use value in /DEF_SHELL.
= 1
Yes.
= 2 Default, if /DEF_SHELL is not defined
No.

(Integer)

  
P_thickfail Fraction of failed thickness for shell element deletion. 11
0.0 ≤ P _ t h i c k f a i l ≤ 1.0
Fraction of failed thickness.
-1.0 ≤ P_thickfail ≤ 0
Fraction of failed integration point through thickness.

0.0 ≤ P _ t h i c k f a i l ≤ 1.0 MathType@MTEF@5@5@+= feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqGqFfpeea0xe9vq=Jb9 vqpeea0xd9q8qiYRWxGi6xij=hbba9q8aq0=yq=He9q8qiLsFr0=vr 0=vr0db8meaabaqaciGacaGaaeqabaWaaeaaeaaakeaacaaIWaGaai OlaiaaicdacqGHKjYOcaWGqbGaai4xaiaadshacaWGObGaamyAaiaa dogacaWGRbWaaSbaaSqaaiaadAgacaWGHbGaamyAaiaadYgaaeqaaO GaeyizImQaaGymaiaac6cacaaIWaaaaa@4966@ (Real)

Default = 1.0 (Real)

  
hm Shell membrane hourglass coefficient. 5

Only used when Ishell=1, 2, 3, 4.

Default = 0.01 for Ishell =1, 2, 4.

Default = 0.1 for Ishell = 3.

(Real)

  
hf Shell out-of-plane hourglass. 5

Only used when Ishell=1, 2, 3, 4.

Default = 0.01 (Real)

  
hr Shell rotation hourglass coefficient. 5

Only used when Ishell=1, 2, 3, 4.

Default = 0.01 for Ishell =1, 2, 4.

Default = 0.1 for Ishell = 3.

(Real)

  
dm Shell Membrane Damping

For default values, refer to the table in Comment 7.

(Real)

  
dn Shell numerical damping. 6

It is only used for Ishell =12, 24 and Ish3n = 30

Default =0.015 for Ishell =24 (QEPH)

Default =0.001 for Ishell =12 (QBAT)

Default =0.0001 for Ish3n =30 (DKT18)

(Real)

  
N Number of integration points through the thickness with 0 < N < 10. 10
= 0 (Default)
Means global integration model for material LAW1, and automatically set N=3 for other material laws.
= 1
Membrane behavior.

(Integer)

  
Thick Shell thickness.

(Real)

 [ m ]
Ashear Shear factor.

Default is Reissner value: 5/6 (Real)

  
Ithick Shell resultant stresses calculation flag. 8
= -1
Automatically set the best value according to element type and material law.
= 0
Use value in /DEF_SHELL.
= 1
Thickness change is taken into account.
= 2 Default, if /DEF_SHELL is not defined
Thickness is constant.

(Integer)

  
Iplas Shell plane stress plasticity flag. 9
It is available for material laws 2, 22, 27 and 36.
= -1
Automatically set the best value according to element type and material law.
= 0
Use value in /DEF_SHELL.
= 1 Default for LAW36 and global integration.
Iterative projection with three Newton iterations.
= 2 Default, if /DEF_SHELL is not defined or for LAW2 and global integration
Radial return.

(Integer)

  

Comments

  1. Ishell - Shell small strain formulation flag
    • Ishell=1,2,3,4 (Q4): original 4 node Radioss shell with hourglass perturbation stabilization
    • Ishell=24 (QEPH): formulation with hourglass physical stabilization for general use
    • Ishell=12 (QBAT): modified BATOZ Q4γ24 shell with four Gauss integration points and reduced integration for in-plane shear. No hourglass control is needed for this shell
    • Ishell=2 is incompatible with one integration point (through thickness) for shell element
  2. Ish3n - 3 node shell element formulation flag
    • Ish3n=30 (DKT18): BATOZ DKT18 thin shell with three Hammer integration points
  3. Idrill - Drilling degree of freedom stiffness flag
    • Drilling DOF stiffness is recommended for implicit solutions especially for Riks method and bending dominated problems
    • Idrill is available for QEPH, QBAT (Ishell =12, 24), and standard triangle (C0) shell elements (Ish3n = 1, 2)
  4. Ismstr - Small strain formulation
    • Small strain formulation is activated from time t=0, if Ismstr =1 or 3. It may be used for a faster preliminary analysis, but the accuracy of the results is not ensured.
    • Any shell for which Δt   <   Δt min MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbbG8FasPYRqj0=yi0dXdbba9pGe9xq=JbbG8A8frFve9 Fve9Ff0dmeaabaqaciGacaGaaeqabaWaaeaaeaaakeaacaqGuoGaae iDaiaayIW7caqG8aGaaGjcVlaabs5acaqG0bWaaSbaaSqaaiaab2ga caqGPbGaaeOBaaqabaaaaa@415B@ can be switched to a small strain formulation by Radioss Engine option /DT/SHELL/CST; except if Ismstr =4.
    • If the small strain option is set to 1 or 3, the strains and stresses which are given in material laws, are engineering strains and stresses; otherwise they are true strains and stresses.
    • Ismstr =10 is only compatible with these material laws 42, 62, 69, and 82 that use total strain formulation. Generally, the Left Cauchy-Green strain is used. For User laws, the deformation gradient tensor and the right stretch tensor may be used.
  5. hm, hf, and hr - Hourglass coefficients
    • Are only used for Q4 shells (Ishell=1,2,3,4). They must have a value between 0 and 0.05.
    • For Ishell=3, the default values of hm and hr are 0.1 with larger values possible.
  6. dn - Shell numerical damping coefficient
    • dn is only used for Ishell =12, 24 and Ish3n = 30
      • Ishell =24 (QEPH) dn is used for hourglass stress calculation
      • Ishell =12 (QBAT) dn is used for all stress terms, except transvers shear
      • Ish3n =30 (DKT18) dn is only used for membrane
  7. Default value for numerical damping coefficient dm.
      dm
    Ishell= 1, 2, 3, 4 (Q4) 0.05 for LAW27

    0.0 for LAW32, 36
    Ishell=12 (QBAT) 0.0 for LAW2, 27, 32, 36
    Ishell=24 (QEPH) 0.015 for all other material
    Ish3n= 1, 2, 31 0.0
    Ish3n=30 (DKT18) 0.0
    Any Ishell, Ish3n 0.05 for LAW65
  8. Ithick - Shell resultant stresses calculation flag
    • Ithick is automatically set to 1 for material LAW32
    • Ithick =1, the small strain option is automatically deactivated in the corresponding type of element
  9. Iplas - Shell plane stress plasticity flag
    • It is recommended to use Iplas =1, if Ithick =1
    • If Iplas =1, the small strain option is automatically deactivated in the corresponding type of element
  10. Global integration, N=0
    • Global integration is only compatible with material LAW1.
    • Failure models are not available with global integration for shells.
    • State files (/STATE/DT which creates /INISHE and /INISH3N) are not compatible with global integration.
    • Automatically set to N=3 for the other material laws.
  11. Element deletion rules used with P_thickfail and failure models:
    • P_thickfail defined in both the property and in the failure model(s) (/FAIL) are considered to trigger the element failure.
      • P_thickfail > 0 defines a fraction of failed thickness. This uses the amount of thickness assigned to each integration point.
      • P_thickfail < 0 defines a ratio of failed integration points. This uses the number of integration point.
      • Minimum of the absolute value defined in the shell property or in the failure criterion card is used to trigger the element failure.
    • For fully-integrated shells (Ishell=12), the rules described above for under-integrated shells applies to each Gauss point separately. P_thickfail criterion is checked for all integration point thickness for each in-plane Gauss point. The element is deleted only when all Gauss points reach P_thickfail criterion.
    • P_thickfail defined in the property and in the failure model(s) (/FAIL) must use the same sign. Otherwise, the P_thickfail defined in the property takes the same sign as the value defined in the failure criterion card /FAIL.
    • P_thickfail rules are not used with failure models defined inside the material laws. It is used only for the failure model defined with /FAIL.
    • By default, P_thickfail = 1.0 in the property.