/MAT/LAW19 (FABRI)

Format

(1)	(3)	(5)	(7)	(9)
/MAT/LAW19/`mat_ID`/`unit_ID` or /MAT/FABRI/`mat_ID`/`unit_ID`
`mat_title`
$ρ_{i}$
`E`₁₁	`E`₂₂	$ν_{12}$
`G`₁₂	`G`₂₃	`G`₃₁
`R`_E		`ZeroStress`	`Fscale_Por`	`sens_ID`

Definitions

Field	Contents	SI Unit Example
`mat_ID`	Material identifier (Integer, maximum 10 digits)
`unit_ID`	Unit Identifier (Integer, maximum 10 digits)
`mat_title`	Material title (Character, maximum 100 characters)
$ρ_{i}$	Initial density (Real)	$[\frac{k g}{m^{3}}]$
`E`₁₁	Young's modulus in direction 1. (Real)	$[Pa]$
`E`₂₂	Young's modulus in direction 2. (Real)	$[Pa]$
$ν_{12}$	Poisson's ratio. (Real)
`G`₁₂	Shear modulus. (Real)	$[Pa]$
`G`₂₃	Shear modulus. (Real)	$[Pa]$
`G`₃₁	Shear modulus. (Real)	$[Pa]$
`R`_E	Reduction factor value. Minimum value, `R`_E > 0.001 Default =1.0 (Real)
`ZeroStress`	Zero stress flag. = 0 . = 1 Full stress reduction - compressive and tensile initial stresses are set to zero up to the reference state. This option must be used if the airbag folder has generated initial tensile stresses. (Real)
`Fscale_Por`	FVM internal scale factor of surface porosity. 3 Default set to 0.0 (Real)
`sens_ID`	Sensor identifier. 4 (Integer, maximum 10 digits)

Example (Airbag)

#RADIOSS STARTER
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/UNIT/1
unit for mat
                  Mg                  mm                  ms
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#-  2. MATERIALS:
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/MAT/FABRI/1/1
Fabric
#              RHO_I  
              1.5e-9        
#                E11                 E22                NU12
                 500                 500                   0
#                G12                 G23                 G31
                  10                  10                  10
#                R_E                              ZEROSTRESS          Fscale_pro   SENS_ID
                 .01                                       0                   0         0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#ENDDATA
/END
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

Comments

Material Law 19 must be used with /PROP/TYPE9 (SH_ORTH) (Orthotropic shell element).
The reduction factor R_E is used to ease the Young's modulus when the airbag fabric is in compression:

Figure 1.
Fscale_Por is used in LAW19 with surf_ID_in > 0 in either the /MONVOL/FVMBAG (Obsolete) or /MONVOL/FVMBAG1 card, to define internal surface porosity ranging from 0 (no porosity) up to 1 (full porosity).
The sens_ID is used only with ZeroStress > 0 and reference state geometry. This ensures the stability of the mesh deformed from the reference configuration. The pre-constrained state will be released at the time determined by the sensor activation. This is useful for airbags with a delayed expansion time.