/MAT/LAW84

Block Format Keyword

/MAT/LAW84 - Swift and Voce Elastoplastic Law

Description

Swift-Voce elastoplastic law with Johnson-Cook strain rate hardening and temperature softening. This law allows modeling a quadratic non-associated flow rule.

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
/MAT/LAW84/mat_ID/unit_ID
mat_title

E
P12		P22		P33		Q		B
G12		G22		G33		K0
A				n		C
η		Cp		Tini		Tref		Tmelt
m

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)
P12	Yield parameter Default = -0.5 (Real)
P22	Yield parameter Default = 1.0 (Real)
P33	Yield parameter Default = 3.0 (Real)
G12	Flow rule parameter Default = P12 (Real)
G22	Flow rule parameter Default = P22 (Real)
G33	Flow rule parameter Default = P33 (Real)
K0	Voce parameter (Real)
	Yield weighting coefficient Default = 0.0 (Real)
Q	Voce hardening coefficient (Real)
B	Voce plastic strain coefficient Default = 0.0 (Real)
A	Swift hardening coefficient (Real)
n	Swift hardening exponent Default = 1.0 (Real)
	Swift hardening parameter Default = 0.00 (Real)
C	Strain rate coefficient Default = 0.00 (Real) = 0: no strain rate effect
	Reference strain rate Default = 1030 , no strain rate effect (Real)
η	Taylor-Quinney coefficient quantifies the fraction of plastic work converted to heat (Real)
Cp	Specific heat (Real)
Tini	Initial temperature used in initialization when time=0 (Real)
Tref	Reference temperature (Real)
Tmelt	Melting temperature (Real)
m	Temperature exponent (Real)
	Strain rate optimization parameter for temperature dependency (Real)

(Metal)

#RADIOSS STARTER

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/UNIT/1

unit for mat

Mg mm s

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#- 2. MATERIALS:

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/MAT/LAW84/1/1

Swift-voce (metal)

# RHO_I

8E-9

# E NU

206000. 0.30

# P12 P22 P33 QVOCE BVOCE

-0.5 1. 3. 524.0000 25.

# G11 G22 G33 K0 ALPHA

-0.5 1. 3. 100. 0.5

# AN EPS0 NN CEPSP DEPS0

1000. 0.00128 0.200 0.014 0.0011

# ETA CP TINI TREF TMELT

0.9 420e+8 293 293. 1700.

# MTEMP DEPSAD

0.921 1.379

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#ENDDATA

/END

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1.	Yield stress is computed using an analytic expression with a combination of both Swift and Voce models, the strain rate dependency and temperature dependency following Johnson-Cook law.

2.	The effective stress is computed as follows:

3.	Temperature is updated using:

Where,