/DEF_SOLID

Block Format Keyword

/DEF_SOLID - Solid Default Values Initialization

Description

This keyword is used to set default values for certain parameters in solid property (/PROP/SOLID and /PROP/TSHELL).

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
/DEF_SOLID
Isolid	Ismstr		Istrain			Imas	Iframe

Field	Contents
Isolid	Solid elements formulation flag (Integer) = 0: default, set to 1. = 1: Standard 8-node solid element, one integration point. Viscous hourglass formulation with orthogonal and rigid deformation modes compensation (Belytschko). = 2: Standard 8-node solid element, one integration point. Viscous hourglass formulation without orthogonality (Hallquist). = 12: Standard 8-node solid, full integration (no hourglass) - OBSOLETE - Use Isolid =17 (H8C). = 14: HA8 locking-free 8-node solid or thick shell elements, co-rotational, full integration, variable number of Gauss points. = 15: HSEPH/PA6 thick shell elements (8-node and 6-node respectively). Co-rotational, under integrated (one Gauss point in the plane) with physical stabilization. Variable number of integration points in thickness direction. = 16: Quadratic 16-node thick shell or Quadratic 20-node solid, full integration, variable number of Gauss points in all directions. = 17: H8C compatible solid full integration formulation = 24: HEPH 8-node solid element. Co-rotational, under-integrated (one Gauss point) with physical stabilization.
Ismstr	Small strain formulation flag (Integer) = 0: default, set to 4. = 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) = 10: Lagrange type total strain.
Istrain	Computes strains for post-processing flag (Integer) = 0: default, set to 2 = 1: yes = 2: no
Imas	Nodal mass distribution (per element) flag (only for tetra4 and tetra10 element) (Integer) = 0: default, set to 2 = 1: distribution taking into account nodal volume angle = 2: homogeneous distribution
Iframe	Element coordinate system formulation flag (only for standard 8-node bricks: Isolid =1, 2, 12, or 17) (Integer) = 0: default, set to 1 = 1: non co-rotational formulation = 2: co-rotational formulation

1.	This card is read only once. Only the first card /DEF_SOLID written in the model is used. The other card /DEF_SOLID are ignored.

2.	The flag Isolid is ignored with 4-node and 10-node tetrahedron elements. For these elements the number of integration points is fixed (1 and 4, respectively).

3.	If Isolid =12, brick deviatoric behavior is computed using 8 Gauss points; bulk behavior is still under-integrated to avoid element locking. This option is currently compatible with material laws 1, 3, 28, 29, 30, 31, 33, 34, 35 and 36.

4.	Small strain:

If the small strain option is set to 1, the strains and stresses used in material laws are engineering strains and stresses. Otherwise, they are true strains and stresses.

Small strain option is not compatible with fully integrated 8-point elements (Isolid =12). In this case, the flag switches to Ismstr =4, and the Ismstr flag in /DEF_SOLID is ignored.

The RADIOSS Engine option /DT/BRICK/CST will only work for brick property sets with Ismstr =2. The flag Ismstr =10 is only compatible with some material laws using total strain formulation (example, Laws 38, 42, 69 and 82). The Left Cauchy-Green strain is used for Laws 38, 42, 69 and 82, the Green-Lagrange strain otherwise.

5.	Co-rotational formulation:

If the Isolid =1, 2, or 12 and Iframe =2, the stress tensor is computed in a co-rotational coordinate system. This formulation is more accurate if large rotations are involved, at the expense of higher computation cost. It is recommended in case of elastic or visco-elastic problems with important shear deformations. Co-rotational formulation is compatible with 8-node bricks and quads.

6.	HEPH and HSEPH elements: hourglass formulation is similar to QEPH shell elements.

7.	HA8: Locking-free general solid or thick shell formulation, co-rotational. HA8 formulation is compatible with all material laws.

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

9.	The hourglass formulation is viscous for Isolid =0, 1, or 2.

10.	If the small strain option is set to 1, the strains and stresses which are given in material laws are engineering strains and stresses. Otherwise, they are true strains and stresses.

11.	The flag Ismstr =10 is only available with 8 node solid element (not available with Isolid =12) and 4-node solid elements.

12.	The 8 Gauss points formulation (Isolid =12) is not available for Ismstr =1, 2, or 3 (8 Gauss points formulation switches to Ismstr =4 in any case), and 10.

13.	Strains for post-processing are computed whatever the value of the Istrain flag for material laws 14, 24 and material laws larger than 28.

14.	Imas is used only for tetra4 and tetra10 element, the distribution of Imas =1 is more realistic with irregular mesh and might be more stable.

Solid Flag Isolid

Isolid (0)	4 Node 2D Quad	8 Node hexahedron	4 Node tetrahedron	6 Node pentahedron	10 Node tetrahedron	16 Node hexahedron	20 Node hexahedron
1		Hourglass 1	1 Gauss Point (1)		4 Gauss Points (1)
2	Hourglass 2 (1)	Hourglass 2
12		8 Gauss points
14		HA8 thick shell or solid
15		HSEPH thick shell		PA6 thick shell
16						quadrat. thick shell	quadrat. solid
17		H8C solid
24		co-rotational HEPH

•	(0) only if Isolid =1, 2, or 12 the Iframe default is 0. If Iframe =2, it is a co-rotational formulation.

Number of integration points for Isolid =14, 15, 16 the Inpts default is 222 (directions i, j, k). Otherwise, this input is specified in the property types: /PROP/SOLID, /PROP/….

•	(1) default value; a different input value is ignored.