/INIBRI/STRS_F

Block Format Keyword Describes the initial state (full stress in local system, values for each integration point) for a brick.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
/INIBRI/STRS_F/`unit_ID`

If STRS_F and 8-node solid element with 1 or 8 integration points

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
`brick_ID`	`Nb_integr`	`Isolnod`	`Isolid`	`nptr`	`npts`	`nptt`	`nlay`	`grbric_ID`

For each integration point (Nb_integr = 0)

(1)	(3)	(5)
`E`_int	$ρ$
$σ_{1}$	$σ_{2}$	$σ_{3}$
$σ_{12}$	$σ_{23}$	$σ_{31}$
$ε_{p}$

If STRS_F and 16-node or 20-node solid elements, 8-node HA8 element; 8-node HSEPH elements, 6-node PA6 elements, 10-node tetrahedron or Pentahedron 6-nodes.

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
`brick_ID`	`Nb_integr`	`Isolnod`	`Isolid`	`nptr`	`npts`	`nptt`	`nlay`	`grbric_ID`

For each integration point (Nb_integr > 0)

(1)	(3)	(5)
$σ_{1}$	$σ_{2}$	$σ_{3}$
$σ_{12}$	$σ_{23}$	$σ_{31}$
$ε_{p}$	`E`_int	$ρ$

Definitions

Field	Contents	SI Unit Example
`unit_ID`	Unit Identifier. (Integer, maximum 10 digits)
`brick_ID`	Element identifier. (Integer)
`Nb_integr`	Number of integration points. Corresponds to the property definition of this element. (Integer)
`Isolnod`	Number of nodes of solid element. (Integer)
`Isolid`	Solid element formulation. Corresponds to the solid element formulation in property definition of this element. (Integer)
`nptr`	Number of integration points in direction r. (Integer)
`npts`	Number of integration points in direction s. (Integer)
`nptt`	Number of integration points in direction t. (Integer)
`nlay`	Number of layers for thick shell elements. (Integer)
`grbric_ID`	Brick group identifier. 4 (Integer)
$ε_{p}$	Plastic strain. (Real)
$σ_{1}$	Stress. (Real)
$σ_{2}$	Stress. (Real)
$σ_{3}$	Stress. (Real)
$σ_{12}$	Shear stress. (Real)
$σ_{23}$	Shear stress. (Real)
$σ_{31}$	Shear stress. (Real)
`E`_int	Internal energy of solid element. (Real)
$ρ$	Volumetric mass. (Real)

Comments

The initial state for brick may be defined by more than one block.
If Nb_integr > 1, the optional continuation lines must be repeated for each integration point, if Keyword2 = STRS_F and 8-node solid element with 1 or 8 integration point.
Format Line 4; Format Line 5; Format Line 6
If Nb_integr > 1, the optional continuation lines have to be repeated for each integration point, if Keyword2 = STRS_FGLO and 16-node or 20-node solid elements, 8-node HA8 elements, 8-node HSEPH elements, 6-node PA6 elements; 8-node HSEPH elements, 6-node PA6 elements, 10-nodes tetrahedron or Pentahedron 6 nodes.
Format Line 3; Format Line 4; Format Line 5
Only one block of stress values needs to be defined when the elements are defined with the group of bricks grbric_ID. The values defined in the block will be applied to all elements in the group of bricks. All the elements defined in group of bricks must belong to the same part (/PART).
Using /INIBRI/STRS_F, you are assuming there is no density of the deformed elements. Before the first cycle, Radioss will check consistency of the input stress tensor with material data (stiffness and density):(1)
$D = \frac{s_{11} + s_{22} + s_{33}}{3} - B u l k \cdot (1 - \frac{ρ}{ρ_{0}}) = 0$

Where,

$ρ_{0}$

Density defined in the Starter file.

$ρ$

Density in the state file.

If the stress is not fulfilled, Radioss will correct the diagonal entry of the stress tensor: (2)
$σ_{i}^{i n i t i a l} = σ_{i}^{i n p u t} - D$

( $i$ =1,2,3)