/PROP/TYPE20 (TSHELL)

Block Format Keyword

/PROP/TYPE20 - General Thick Shell Property Set

Description

This property is used to define the general thick shell property set.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
/PROP/TYPE20/prop_ID/unit_ID or /PROP/TSHELL/prop_ID/unit_ID
prop_title
Isolid	Ismstr		Icpre	Icstr	Inpts	Iint		dn
qa		qb		h
		Istrain

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)

Isolid

Solid elements formulation flag

(Integer)

= 14: HA8 locking-free 8-node thick shell element, co-rotational, full integration, variable number of Gauss points in all directions.

= 15: HSEPH/PA6 thick shell elements (8-node and 6-node respectively). Co-rotational, under integrated (1 Gauss point in the plane) with physical stabilization. Variable number of integration points in thickness direction.

= 16: Quadratic 16-node thick shell, full integration, variable number of Gauss points in all directions.

Ismstr

Strain formulation flag

(Integer)

= 0: default, set to value defined in /DEF_SOLID

= 1: small strain from time =0

= 2: full geometric nonlinearities with possible small strain formulation in RADIOSS Engine (/DT/BRICK/CST)

= 3: simplified small strain formulation from time =0 (non-objective formulation)

= 4: full geometric nonlinearities (/DT/BRICK/CST has no effect)

Icpre

Constant pressure formulation flag

(Integer)

= 0: no reduced pressure formulation

= 1: reduced pressure formulation

= 2: variable state between Icpre = 0 and Icpre = 1 in function of plasticity

Icstr

Constant stress formulation flag (HA8 only)

(Integer)

= 0: no reduced stress integration

= 001: reduced stress integration in t direction

= 010: reduced stress integration in s direction

= 100: reduced stress integration in r direction

Inpts

Number of integration points

(Integer)

= j:	1 < j < 9 for Isolid =15

= ijk:

2 < i,j,k < 9 for Isolid =14

= ijk:

2 < i,k < 3, 2 < j < 9 for Isolid =16

where:

i = number of integration points in r direction

j = number of integration points in s direction

k = number of integration points in t direction

Iint

Thickness integration formulation (Isolid =16 only)

(Integer)

= 0: default set to 1

= 1: Gauss integration scheme

= 2: Lobatto integration scheme

Numerical damping for stabilization (Isolid =15 only)

Default = 0.1 (Real)

Quadratic bulk viscosity

Default = 1.10 (Real)

Default = 0.0 for /MAT/LAW70

Linear bulk viscosity

Default = 0.05 (Real)

Default = 0.0 for /MAT/LAW70

Hourglass viscosity coefficient

Default = 0.10 (Real)

Minimum time step

Default = 106 (Real)

Istrain

Compute strain post-processing flag (Comment 12)

(Integer)

= 0: default set to value defined in /DEF_SOLID

= 1: yes

= 2: no

1.	HSEPH elements: hourglass formulation is similar to QEPH shell elements.

2.	HA8: Locking-free thick shell formulation, co-rotational. The number of Gauss points is defined by the Inpts flag: for example, combined with Inpts =252 shows two in r and t directions and five in s direction.

3.	HA8 element must use constant stress formulation.

4.	Lagrange type total strain (Ismstr =10) is not available with thick shells.

If the small strain option is set, the strains and stresses used in material laws are engineering strains and stresses. Otherwise, they are true strains and stresses.

5.	The small strain option is available for HA8 and HSEPH shells. The RADIOSS Engine option /DT/BRICK/CST will only work for brick property sets with Ismstr =2.

6.	Flag Icstr is only used for HA8. The reduced integration for stress direction is made in the thickness direction (local s axis), but it may be combined with other direction (Icstr =011).

7.	Numerical damping dn is only used in hourglass stress calculation for HSEPH (Isolid =15).

8.	For post-processing solid element stress, refer to /ANIM/STRESS for animation and /TH/BRICK for plot files.

9.	It is valid to use the Lobatto integration point in thickness with Isolid < 0 (for quadratic 16-node thick shell only).

10.	Hourglass viscosity coefficient h must have a value between 0 and 0.15 and is not active with 8 integration point solids.

11.	When property is used with /MAT/LAW1, with Isolid =15 and number of integration points is different from one, number of integration points is set at two (enough to compute correct bending).

12.	The Istrain flag is not used with Material Laws 14, 24 and Material Laws greater than 28. For these materials, the strains for post-processing are always computed.