/MAT/LAW43 (HILL

Block Format Keyword

/MAT/LAW43 - Hill Orthotropic Material

Description

This law describes the Hill orthotropic material and is applicable only to shell elements. This law differs from LAW32 (HILL) only in the input of yield stress (here it is defined by a user function).

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
/MAT/LAW43/mat_ID/unit_ID or /MAT/HILL_TAB/mat_ID/unit_ID
mat_title

E
fct_IDE		Einf		CE
r00		r45		r90		Chard		Iyield0

fct_IDi		Fscalei

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)
E	Young’s modulus (Real)
	Poisson’s ratio (Real)
fct_IDE	Function identifier for the scale factor of Young modulus, when Young modulus is function of the plastic strain (Comment 12). Default = 0: in this case the evolution of Young depends on Einf and CE. (Integer)
Einf	Saturated Young’s modulus for infinitive plastic strain (Real)
CE	Parameter for Young’s modulus evolution (Comment 12) (Real)
r00	Lankford parameter 0 degree (Comment 3) Default = 1.0 (Real)
r45	Lankford parameter 45 degrees Default = 1.0 (Real)
r90	Lankford parameter 90 degrees Default = 1.0 (Real)
Chard	Hardening coefficient (Real) = 0: hardening is full isotropic model = 1: hardening uses the kinematic Prager-Ziegler model = between 0 and 1: hardening is interpolated between the two models
Iyield0	Yield stress flag (Integer) = 0: average yield stress input = 1: yield stress in orthotropic direction 1
	Failure plastic strain Default = 1.0 x 1030 (Real)
	Tensile failure strain at which stress starts to reduce Default = 1.0 x 1030 (Real)
	Maximum tensile failure strain at which the stress in element is set to zero Default = 2.0 x 1030 (Real)
fct_IDi	Plasticity curves ith function identifier (Integer)
Fscalei	Scale factor for ith function Default set to 1.0 (Real)
i	Strain rate for ith function (Real)

#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/HILL_TAB/1/1

metal

# RHO_I

# E NU

206000 .3

#FUNCT_IDE EINF CE

0 0 0

# r00 r45 r90 C_hard Iyield0

1.73 1.34 2.24 0 0

# EPSP_max EPS_t1 EPS_m

0 0 0

# func_IDi Fscale_i EPS_dot_i

5 0 0

#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

#- 3. FUNCTIONS:

#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

/FUNCT/5

metal

# X Y

0 260

.002 270

.005 280

.01 297

.02 322

.05 370

.1 422

.15 457

.2 485

.3 528

#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

#ENDDATA

/END

#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|

1.	This material law must be used with property set /PROP/TYPE9 (SH_ORTH) or /PROP/TYPE10 (SH_COMP).

2.	The yield stress is defined by a user function and the yield stress is compared to equivalent stress:

3.	Angles for Lankford parameters are defined with respect to orthotropic direction 1.

The Lankford parameters ra is the ratio of plastic strain in plane and plastic strain in thickness direction .

Where, α is the angle to the orthotropic direction 1.

This Lankford parameters ra could be determined from a simple tensile test at an angle α.

A higher value of R means better formability.

4.	If the last point of the first (static) function equals 0 in stress, default value of is set to the corresponding value of .

5.	Element deletion:

•	Once (plastic strain) reaches , in one integration point, the element is deleted.

•	If reaches , the stress is reduced using the following relation:

•	If (largest principal strain) reaches (), the stress in element is reduced to 0 (but the element is not deleted).

•	Once (largest principal strain) reaches (maximum tensile failure strain), the element is deleted.

6.	The maximum number of curves that can be input is 10.

7.	If , the yield is interpolated between and .

8.	If , function is used.

9.	Above , yield is extrapolated.

mat_law43_yield

10.	Radial return is not available (only iterative plasticity).

11.	If the yield stresses have been obtained in the orthotropic direction 1, define Iyield0 =1; otherwise Iyield0 =0.

12.	The evolution of Young’s modulus:

•	If fct_IDE > 0, the curve defines a scale factor for Young modulus evolution with equivalent plastic strain , which means the Young Modulus is scaled by the function :

The initial value of the scale factor should be equal to 1 and it decreases.

•	If fct_IDE = 0, the Young Modulus is calculated as:

Where, E and Einf are respectively the initial and asymptotic value of Young’s modulus, and is the accumulated equivalent plastic strain.

Note: If fct_IDE = 0 and CE = 0, Young modulus E is kept constant.

/MAT/LAW43 (HILL_TAB)

/MAT/LAW43 (HILL_TAB)

/MAT/LAW43 (HILL_TAB)

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