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laws:minty3

MINTY3

Description

Anisotropic elasto-plastic law based on texture for solid elements at constant temperature.

Microscopic INTerpolated Yield locus 3D

The model

This law is used for mechanical analysis of elasto-plastic anisotropic solids undergoing large strains. Isotropic hardening is assumed.

Files

Prepro: LMINTY.F
Lagamine: MINTY3.F

Availability

Plane stress state NO
Plane strain state NO
Axisymmetric state NO
3D state YES
Generalized plane state NO

Input file

Parameters defining the type of constitutive law

Line 1 (2I5, 60A1)
ILLaw number
Texture data being read as metallurgical data, this constitutive law MUST BE THE FIRST one (IL=1)
ITYPE 502
COMMNT Any comment (up to 60 characters) that will be reproduced on the output listing

Integer parameters

Line 1 (8I5)
NINTV Number of sub-steps used to integrate numerically the constitutive equation in a time step
NCRI Number of crystals for each integration point (400 or 1600)
(to be in accordance with *.MET)
NNLP Maximum number of steps without re-actualisation of the yield locus
NTEMPO Number of TEMPO variables per integration point
(NTEMPO=100 for IMETH=5, 7, 9 or 11 and NTEMPO=109 for IMETH=6, 8, 10 or 12)
IMETH Type of anisotropic yield surface to be used
= -1 : No updated HILL with no discretized yield locus
= +1 : No updated HILL with discretized yield locus
= -2 : No updated J. WINTERS with no discretized yield locus (6 order series in stresses space)
= +2 : No updated B. van BAEL with discretized yield locus (6 order series in strains space)
= +3 : No updated U.L.G. yield locus
= +4 : Updated U.L.G. yield locus
= +5 : Taylor model without updating
= +6 : Taylor model with updating
= +7 : Bishop-Hill model without updating
= +8 : Bishop-Hill model with updating
= +9 : Visco-plastic Taylor model without updating
= +10 : Visco-plastic Taylor model with updating
= +11 : ALAMEL model without updating
= +12 : ALAMEL model with updating
IKAP = 0 : Analytical compliance matrix
= 1 : Perturbation compliance matrix
MAXIT
NINTEPS Number of sub-intervals per unit of delta epsilon

Thus, the number of sub-steps = MAX(NINTV; NINTEPS*DELTA EPSILON).

Real parameters

Line 1 (6G10.0)
E YOUNG's elastic modulus
ANU POISSON's ratio
CK Hardening factor K (see below)
GAMMA$\phi$ Hardening GAMMA$\phi$ coefficient ($\Gamma^{\circ}$) (see below)
CN Hardening exponent (see below)
THETA$\phi$ Angle between stress nodes for the yield locus interpolation

If IMETH=9 or 10 :

Line 1 (1G10.0)
H Visco-plastic parameter
(=1/$m$ with $m$ the strain rate sensitivity parameter)

Only if IMETH=$\pm$1 (HILL) :

Line 1 : HILL's coefficient
ALPHA12 $\alpha_{12}$
ALPHA13 $\alpha_{13}$
ALPHA23 $\alpha_{23}$
ALPHA44 $\alpha_{44}$
ALPHA55 $\alpha_{55}$
ALPHA66 $\alpha_{66}$
Line 2
SIG$\phi$ Uniaxial yield stress in a reference direction

Stresses

Number of stresses

6

Meaning

The stresses are the components of CAUCHY stress tensor in global (X,Y,Z) coordinates.

SIG(1)$\sigma_{xx}$
SIG(2)$\sigma_{yy}$
SIG(3)$\sigma_{zz}$
SIG(4)$\sigma_{xy}$
SIG(5)$\sigma_{xz}$
SIG(6)$\sigma_{yz}$

State variables

Number of state variables

7

List of state variables

Q(1) Accumulated plastic strains
Q(2) GAMMA hardening parameter ($\Gamma$)
Q(3)$\rightarrow$Q(7) 5 components of the plastic strain rate direction

Hardening form

- For IMETH$\neq$1 : in this case, the yield surface is scaled by the critical resolved shear stress $\tau$ : \[\tau=K(\Gamma^{\circ}+\Gamma)^N\] - For IMETH=1 : in this case, the yield surface is scaled by $\sigma_{eq}$ : \[\sigma = K(\varepsilon_0+\varepsilon)^n\]

File *.MET for META=4 , IMETH=5 to 12.

For each material :

Line 1 (1I5)
NGLI Number of slip system in the crystal
Line 2-3-4-… (NGLI lines) (8G10.0)
NORMAL(3) Vector $\perp$ to the slip plane
DIRECTION(3) Vector direction of the slip
CRSS+ Critical resolved shear stress + if slip in positive direction
CRSS- Critical resolved shear stress - otherwise
Line 2 + NGLI and following ones (NCRI lines) (I5,4(1F13.5)
ICRI Crystal number (increasing order from 1 to NCRI)
WEIGHT Crystal weight
EULER Euler angles to define crystal orientation
Phi_1 / Phi / Phi _2
laws/minty3.txt · Last modified: 2020/08/25 15:46 (external edit)