/MAT/LAW19 (FABRI)

Block Format Keyword

/MAT/LAW19 - Elastic Orthotropic Material

Description

This law defines an elastic orthotropic material and is available only for shell elements. It is used to model airbag fabrics.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
/MAT/LAW19/mat_ID/unit_ID or /MAT/FABRI/mat_ID/unit_ID
mat_title

E11		E22
G12		G23		G31
RE				ZeroStress			Isurf_Por	sens_ID

Field	Contents	SI Unit Example
mat_ID	Material identifier (Integer, maximum 10 digits)
unit_ID	Optional unit identifier (Integer, maximum 10 digits)
mat_title	Material title (Character, maximum 100 characters)
	Initial density (Real)
E11	Young‘s modulus in direction 1 (Real)
E22	Young’s modulus in direction 2 (Real)
	Poisson’s ratio (Real)
G12	Shear modulus (Real)
G23	Shear modulus (Real)
G31	Shear modulus (Real)
RE	Reduction factor value Default set to 1.0 (Real)
ZeroStress	Zero stress flag (Real) = 0: No stress reduction = 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.
Isurf_Por	FVM internal surface porosity (Comment 3) =0: no porosity =1: full porosity (vent) Default set to 0.0 (Integer)
sens_ID	Sensor identifier (Comment 4) (Integer, maximum 10 digits)

#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

airbag

# RHO_I

8.49999992E-4

# E11 E22 NU12

500 500 0

# G12 G23 G31

10 10 10

# R_E ZEROSTRESS Isurf_Por 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----|

1.	Material Law 19 must be used with /PROP/TYPE9 (Orthotropic shell element).

2.	The reduction factor RE is used to ease the Young‘s modulus when the airbag fabric is in compression:

clip0060

3.	Isurf_Por is used in LAW19 with surf_IDin > 0 in either the /MONVOL/FVMBAG 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.