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laws:minty3_ki

MINTY3_KI

Description

Anisotropic elasto-plastic law based on texture for solid elements at constant temperature combined with the microstructure hardening model of C. TEODOSIU.

Microscopic INTerpolated Yield locus 3D KInematic

The model

This law is used for mechanical analysis of elasto-plastic anisotropic solids undergoing large strains. Isotropic or Isotropic & Kinematic (Teodosiu) hardening are assumed.

Files

Prepro: LMINTY_KI.F
Lagamine: MINTY3_KI.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 511
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
(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
VOCE

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

Line 1 (1I5)
NTEO = 0 : Classic hardening
= 1 : Teodosiu hardening

If NTEO = 1 :

Line 1 (3I5)
NREAD = 1 : Read the 58 state variables in .f72 (in column)
KREAD = 1 : Changes hardening parameters if fitted with a Von Mises yield locus and shear tests
= 2 : Automatically performed in Lagamine
IOPTEO = 10 : Hofferlin type. $S_L$ only activated if a path change with an elastic transition occurs
= 20 : Alves type. $S_L$ activated for any path change (continuous path change or even local path change, for example simple shear where material frame rotates)
= 21 : Alves type but $S_L$ activated only if a sufficiently strong path change occurs $\rvert\Delta\hat{\varepsilon}_{n+1}^p-\Delta\hat{\varepsilon}_n^p\rvert\geq prec$, where $n$ and $n+1$ are two successive steps and $\Delta\hat{\varepsilon}^p$ is the increment of the local plastic strain

Only if KREAD=1 :

Line 1 (1G10.0)
COEFK Value to correct Teodosiu's parameters

Real parameters

Line 1 (3G10.0)
E YOUNG's elastic modulus
ANU POISSON's ratio
THETA$\phi$ Angle between stress nodes for the yield locus interpolation

If NTEO=1, the 3 following parameters can be equal to 0 :

Line 1 (3G10.0)
CK Hardening factor K (see below)
GAMMA$\phi$ Hardening GAMMA$\phi$ coefficient ($\Gamma^{\circ}$) (see below)
CN Hardening exponent (see below)

If IMETH=9 or 10 :

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

Only if NTEO=1 : Theodosius hardening parameters :

Line 1 (2G10.0)
CP Polarity saturation rate
NP Polarity exponent
Line 1 (5G10.0)
CSD Orientation saturation rate for $S_D$
CSL Orientation saturation rate for $\underline{\underline{S_L}}$
SSAT0 Initial orientation saturation value
NL Orientation exponent
R0 Initial yield limit
Line 1 (2G10.0)
CX Back stress saturation rate
XSAT0 Initial back stress saturation value 
Line 1 (2G10.0)
M Influence of $\underline{\underline{S}} on kinematic ($m=0$) - isotropic ($m=1$) hardening
Q $S_D-\underline{\underline{S_L}}$ balance on $X_{sat}$ 
Line 1 (2G10.0)
CR Isotropic hardening : saturation rate
RSAT Isotropic hardening : saturation value

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 if NTEO=0
= 62 if NTEO=1

List of state variables

If NTEO=0 :

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

If NTEO=1 :

Q(1) IYIELD
= 0 : Elastic
= 1 : Plastic
Q(2) pd (for printing)
Q(3:7) 5 components of the plastic strain rate direction
Q(8:13) 6 components back stress X
Q(20) SD (for printing)
Q(21:56) 36 components of $S_L$
Q(57) $\rvert$S$\rvert$ (for printing)
Q(58) R
Q(59:62) Internal parameters (for printing)

Hardening form

NTEO=0 : - 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 $\sigma_{eq}$ : \[\sigma = K(\varepsilon_0+\varepsilon)^n\]

NTEO=1 : Depicted in internal report

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_ki.txt · Last modified: 2020/08/25 15:46 (external edit)