/MAT/LAW76 (SAMP)

Block Format Keyword

/MAT/LAW76 - Semi-Analytical Plastic Model

Description

This law describes a semi-analytical elasto-plastic material using user-defined functions for the work-hardening portion for tension, compression and shear (stress as function of strain).

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
/MAT/LAW76/mat_ID/unit_ID or /MAT/SAMP/mat_ID/unit_ID
mat_title

E
tab_IDt	tab_IDc	tab_IDs
Fscalet		Fscalec		Fscales				XFAC
		fct_IDpr	Fscalepr		Fsmooth	Fcut
				Dc
fct_ID1			Fscale1
Iform	IQUAD	ICONV

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	Initial Young’s modulus (Real)
	Poisson’s ratio (Real)
XFAC	Scale factor for the second entry (strain rate) of the three tables (Comment 4) Default = 1.0 (Real)
tab_IDt	Tension yield stress table identifier (stress vs. plastic tension strain with the possibility of strain rate dependency) (Integer)
tab_IDc	Compression yield stress table identifier (stress vs. plastic compression strain with the possibility of strain rate dependency) (Integer)
tab_IDs	Shear yield stress table identifier (stress vs. plastic shear strain with the possibility of strain rate dependency) (Integer)
Fscalet	Scale factor for ordinate (stress) for tab_IDt Default = 1.0 (Real)
Fscalec	Scale factor for ordinate (stress) for tab_IDc Default = 1.0 (Real)
Fscales	Scale factor for ordinate (stress) for tab_IDs Default = 1.0 (Real)
	Plastic Poisson’s ratio (Real)
fct_IDpr	Plastic Poisson’s ratio function identifier ( vs. plastic strain) (Real)
Fscalepr	Scale factor for ordinate () in fct_IDpr Default = 1.0 (Real)
Fsmooth	Smooth strain rate option flag Default = 0 (Integer) = 0: no strain rate smoothing = 1: strain rate smoothing active
Fcut	Cutoff frequency for strain rate filtering Default = 1030 (Real)
	Failure plastic strain (start of element damage) Default = 2e30 (Real)
	Maximum plastic strain (element deleted) Default = 2e30 (Real)
Dc	Critical damage (Real)
fct_ID1	Damage function identifier (damage vs plastic strain) (Integer)
Fscale1	Scale factor for ordinate for fct_ID1 Default = 1.0 (Real)
Iform	Formulation flag (Integer) = 0: No associated formulation (default) = 1: von Mises associated formulation
IQUAD	Yield surface flag (Comment 2) (Integer) = 0: Yield surface is linear in the von Mises (default) = 1: Yield surface is quadratic in the von Mises (recommended)
ICONV	Convexity condition flag Default = 0 (Integer) = 1: the convexity is assured = 2: if

#RADIOSS STARTER

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

/UNIT/1

unit for mat

kg mm ms

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

/MAT/LAW76/1/1

LAW76_Material

# RHO_I

1E-6

# E NU

100.0 .3

# TAB_IDt TAB_IDc TAB_IDs

1000 1001 1003

# Fscale_t Fscale_c Fscale_s XFAC

1.000 1.000 1.000 1.000

# NU_p fct_IDpr Fscale_pr Fsmooth Fcut

0.5 0 0 1 1e30

# EPS_f_p EPS_r_p D_c

0 0 0

# fct_ID1 Fscale_1

# IFORM IQUAD ICONV

0 0 1

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

/TABLE/1/1000

curve_list TENSION strain rates

10010 1.0e-4

10020 1.0

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

/FUNCT/10010

eps_vs_sigma funct dt=1.0e-4

0.0000 .100000

1.0000 .200000

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

/FUNCT/10020

eps_vs_sigma funct dt=1.0e-4

0.0000 .100000

1.0000 .200000

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

/TABLE/1/1001

curve_list COMPRESSION strain rates

10030 1.0e-4

10040 1.0

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

/FUNCT/10030

eps_vs_sigma funct dt=1.0e-4

0.0000 .200000

1.0000 .400000

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

/FUNCT/10040

eps_vs_sigma funct dt=1.0e-4

0.0000 .200000

1.0000 .400000

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

/TABLE/1/1003

curve_list SHEAR strain rates

10050 1.0e-4

10060 1.0

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

/FUNCT/10050

eps_vs_sigma funct dt=1.0e-4

0.0000 .050000

0.5000 .060000

1.0000 .065000

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

/FUNCT/10060

eps_vs_sigma funct dt=1.0e-4

0.0000 .050000

0.5000 .060000

1.0000 .065000

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

#ENDDATA

/END

1.	Material is compatible with shell, thick shell and solid elements

2.	Choice of yield surface:

Where,

A0, A1 and A2 coefficients are computed from the hardening curve given for tension, compression and shear.

3.	Choice of formulation:

•	For the no associated plasticity, the flow rule is given by:

•	For the associated plasticity: g = f

4.	The tables should have a maximum dimension equal to 2. The first entry is the plastic strain and the second entry is the strain rate.

5.	User variables USR2, USR3, USR4 are used to output plastic strain components in tension, compression and shear. The output is available both for shells and solids in time history and in animation file