/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)	(7)	(8)	(9)	(10)
/PROP/TYPE1/`prop_ID`/`unit_ID` or /PROP/SHELL/`prop_ID`/`unit_ID`
`prop_title`
`I`_shell	`I`_smstr	`I`_sh3n	`I`_drill		`P_thick`_fail
`h`_m		`h`_f		`h`_r	`d`_m		`d`_n
`N`		`Thick`		`A`_shear		`I`_thick	`I`_plas	`I`_pos

Definition


Field	Contents	SI Unit Example
`prop_ID`	Property identifier. (Integer, maximum 10 digits)
`unit_ID`	(Optional) Unit identifier. (Integer, maximum 10 digits)
`prop_title`	Property title. (Character, maximum 100 characters)
`I`_shell	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)
`I`_smstr	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 `I`_shell = 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)
`I`_sh3n	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)
`I`_drill	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_thick`_fail	Fraction of failed thickness for shell element deletion. 11 -1.0 ≤ `P_thick`_fail ≤ 0 Fraction of failed integration point through thickness. 0.0 ≤ `P_thick`_fail ≤ 1.0 Fraction of failed thickness. Default = 1.0 (Real)
`h`_m	Shell membrane hourglass coefficient. 5 Only used when `I`_shell=1, 2, 3, 4. Default = 0.01 for `I`_shell =1, 2, 4. Default = 0.1 for `I`_shell =3. (Real)
`h`_f	Shell out-of-plane hourglass. 5 Only used when `I`_shell =1, 2, 3, 4. Default = 0.01 (Real)
`h`_r	Shell rotation hourglass coefficient. 5 Only used when `I`_shell=1, 2, 3, 4. Default = 0.01 for `I`_shell =1, 2, 4. Default = 0.1 for `I`_shell =3. (Real)
`d`_m	Shell Membrane Damping For default values, refer to the table in Comment 7. (Real)
`d`_n	Shell numerical damping. 6 It is only used for `I`_shell =12, 24 and `I`_sh3n =30 Default =0.015 for `I`_shell =24 (QEPH) Default =0.001 for `I`_shell =12 (QBAT) Default =0.0001 for `I`_sh3n =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)	$[m]$
`A`_shear	Shear factor. Default is Reissner value: 5/6 (Real)
`I`_thick	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)
`I`_plas	Shell plane stress plasticity flag for material laws 2, 22, 27, 32 and 36. This flag is not used for the other material laws. 9 = -1 Automatically set the best value according to element type and material law. = 0 Use value in /DEF_SHELL. = 1 Iterative projection with three Newton iterations. = 2 Default, if /DEF_SHELL is not defined Radial return. (Integer)
`I`_pos	Mid shell positioning flag. 12 = 0 (Default) No shell offset. = 3 The upper surface is coincident with the element mid-surface. = 4 The lower surface is coincident with the element mid-surface. (Integer)

Example

#RADIOSS STARTER
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#-  1. LOCAL_UNIT_SYSTEM:
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/UNIT/2
unit for prop
#              MUNIT               LUNIT               TUNIT
                  kg                  mm                  ms
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#-  2. GEOMETRICAL SETS:
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PROP/SHELL/1/2
Shell_1mm
#   Ishell    Ismstr     Ish3n    Idrill                            P_thick_fail
        24         0         0         0                                       0
#                 hm                  hf                  hr                  dm                  dn
                   0                   0                   0                   0                   0
#        N   Istrain               Thick              Ashear              Ithick     Iplas      Ipos
         5         0                   1                   0                   1         1         0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#enddata
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

Comments

I_shell - Shell small strain formulation flag
- I_shell =1,2,3,4 (Q4): original 4 node Radioss shell with hourglass perturbation stabilization
- I_shell =24 (QEPH): formulation with hourglass physical stabilization for general use
- I_shell =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
- I_shell =2 is incompatible with one integration point (through thickness) for shell element
I_sh3n - 3 node shell element formulation flag
- I_sh3n =30 (DKT18): BATOZ DKT18 thin shell with three Hammer integration points
I_drill - Drilling degree of freedom stiffness flag
- Drilling DOF stiffness is recommended for implicit solutions especially for Riks method and bending dominated problems
- I_drill is available for QEPH, QBAT (I_shell =12, 24), and standard triangle (C0) shell elements (I_sh3n = 1, 2)
I_smstr - Small strain formulation
- Small strain formulation is activated from time t=0, if I_smstr =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 $Δt < {Δt}_{min}$ can be switched to a small strain formulation by Radioss Engine option /DT/SHELL/CST; except if I_smstr =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.
- I_smstr =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.
h_m, h_f, and h_r - Hourglass coefficients
- Are only used for Q4 shells (I_shell =1,2,3,4). They must have a value between 0 and 0.05.
- For I_shell =3, the default values of h_m and h_r are 0.1 with larger values possible.
d_n - Shell numerical damping coefficient
- d_n is only used for I_shell =12, 24 and I_sh3n =30
  - I_shell =24 (QEPH) d_n is used for hourglass stress calculation
  - I_shell =12 (QBAT) d_n is used for all stress terms, except transverse shear
  - I_sh3n =30 (DKT18) d_n is only used for membrane

Default value for numerical damping coefficient d_m.

	`dm`
`I`_shell= 1, 2, 3, 4 (Q4)	0.05 for LAW27 0.0 for LAW32, 36
`I`_shell=12 (QBAT)	0.0 for LAW2, 27, 32, 36
`I`_shell=24 (QEPH)	0.015 for all other material
`I`_sh3n= 1, 2, 31	0.0
`I`_sh3n=30 (DKT18)	0.0
Any `I`_shell, `I`_sh3n	0.05 for LAW65

I_thick - Shell resultant stresses calculation flag
- I_thick is automatically set to 1 for material LAW32
- I_thick =1, the small strain option is automatically deactivated in the corresponding type of element
I_plas - Shell plane stress plasticity flag
- It is recommended to use I_plas = -1, if I_thick = -1.
- If I_plas =1, the small strain option is automatically deactivated in the corresponding type of element
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.
Element deletion rules used with P_thick_fail and failure models:
- P_thick_fail defined in both the property and in the failure model(s) (/FAIL) are considered to trigger the element failure.
  - P_thick_fail > 0 defines a fraction of failed thickness. This uses the amount of thickness assigned to each integration point.
  - P_thick_fail < 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 (I_shell =12), the rules described above for under-integrated shells applies to each Gauss point separately. P_thick_fail 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_thick_fail criterion.
- P_thick_fail defined in the property and in the failure model(s) (/FAIL) must use the same sign. Otherwise, the P_thick_fail defined in the property takes the same sign as the value defined in the failure criterion card /FAIL.
- P_thick_fail 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_thick_fail =1.0 in the property.
I_pos: Shell position or thickness offset:
- I_pos =0: No shell offset
- I_pos =3: The upper surface is coincident with the element mid-surface.
- I_pos =4: The lower surface is coincident with the element mid-surface.