/PROP/TYPE1 (SHELL)

Block Format Keyword

/PROP/TYPE1 - Shell Property Set

Description

Describes the shell property set which 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
hm		hf		hr		dm		dn
N	Istrain	Thick		Ashear			Ithick	Iplas

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)
Ishell	4 node shell element formulation flag (Integer) = 0: use value in /DEF_SHELL = 1: 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
Ismstr	Shell small strain formulation flag (Comment 3) (Integer) = 0: use value in /DEF_SHELL = 1: small strain from time = 0 (formulation compatible with all other formulation flags) = 2: 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)
Ish3n	3 node shell element formulation flag (Integer) = 0: use value in /DEF_SHELL = 1: standard triangle (C0) = 2: standard triangle (C0) with modification for large rotation = 30: DKT18 = 31: DKT_S3, which based on DTK12 of BATOZ (refer to the Theory Manual)
Idrill	Drilling degree of freedom stiffness flag (Integer) = 0: no = 1: yes
hm	Shell membrane hourglass coefficient Default = 0.01 (Real)
hf	Shell out-of-plane hourglass Default = 0.01 (Real)
hr	Shell rotation hourglass coefficient Default = 0.01 (Real)
dm	Shell membrane damping (Real)
dn	Shell numerical damping (Real)
N	Number of integration points through the thickness with 0 < N < 10 (Comment 15) 0 means global integration model (default) (Integer)
Istrain	Compute strains for post-processing flag (Integer) = 0: default set to value defined with /DEF_SHELL = 1: yes = 2: no
Thick	Shell thickness (Real)
Ashear	Shear factor Default is Reissner value: 5/6 (Real)
Ithick	Shell resultant stresses calculation flag (Integer) = 0: default set to value defined with /DEF_SHELL = 1: thickness change is taken into account = 2: thickness is constant
Iplas	Shell plane stress plasticity flag (Comment 18) (Integer) = 0: default set to value defined with /DEF_SHELL = 1: iterative projection with three Newton iterations = 2: radial return

1.	Q4: original 4 node RADIOSS shell with hourglass perturbation stabilization.

QEPH: formulation with hourglass physical stabilization for general use.

QBAT: modified BATOZ Q4y24 shell with four Gauss integration points and reduced integration for in-plane shear. No hourglass control is needed for this shell.

DKT18: BATOZ DKT18 thin shell with three Hammer integration points.

2.	Flag Ishell = 2 is incompatible with one integration point (through thickness) for shell element.

3.	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 can be switched to a small strain formulation by RADIOSS Engine option /DT/SHELL/CST; except if Ismstr = 4.

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.

5.	hm, hf, and hr are only used for Q4 shells. They must have a value between 0 and 0.05.

6.	For hourglass type 3, hourglass maximum values may be larger, default values are 0.1 for hm and hr.

7.	Shell membrane damping dm is only active for Material Laws 19, 27, 32 and 36:

•	the default value of dm is 5% for Law 27

•	the default value of dm is 25% for Law 19

•	the default value of dm is 0% for Laws 32 and 36

8.	dm is used in any case for QEPH, QBAT shells:

•	the default value of dm for QEPH is 1.5% for Material Laws 19, 27, 32 and 36

•	the default value of dm for QBAT is 0%

For further information about dm coefficient, refer to ‘Shell Membrane Damping’ in the RADIOSS Theory Manual.

9.	dn is only used for Ishell = 12, 24 and Ish3n = 30:

•	for Ishell = 24 dn is used for hourglass stress calculation

•	for QBAT dn is used for all stress terms, except transvers shear

•	for DKT18 dn is only used for membrane

10.	The default value of dn is:

•	1.5% for Ishell =24

•	0.1% for QBAT

•	0.01% for DKT18

11.	If Ithick = 1 or Iplas = 1, the small strain option is automatically deactivated in the corresponding type of element.

12.	Flag Iplas is available for material Laws 2, 22, 27 and 36.

13.	Flag Ithick is automatically set to 1 for Material Law 32.

14.	Flag Istrain is automatically set to 1 for Material Law 27.

15.	Global integration (N= 0) is only compatible with Material Laws 1, 2, 22, 36, 43 and 60. Failure models are not available with global integration for shells.

16.	For material Law 1, an only membrane behavior happens if N= 1. Otherwise, N is ignored and global integration is used.

17.	It is recommended to use Iplas = 1, if Ithick = 1.

18.	The default value for Iplas in case of Law 2 and global integration (N= 0 in shell property) is Iplas = 2: radial return.

The default value for Iplas in case of Law 36 and global integration (N= 0 in shell property) is Iplas = 1: iterative projection.

19.	Idrill is available for QEPH, QBAT (Ishell = 12, 24), and standard triangle (C0) shell elements (Ish3n = 1, 2).

20.	Drilling DOF stiffness is recommended for implicit solutions especially for Riks method and bending dominated problems.