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laws:multidam23d

MULTIDAM23D

Description

Elasto(-visco)-plastic damage law of anisotropic materials for solid elements at constant temperature.

The model

This law is used for mechanical analysis of elasto(-visco)-plastic damage orthotropic solids undergoing large strains, plastic mixed hardening and damage anisotropic hardening are assumed.

Files

Prepro: LMULTIDAM2.F
Lagamine: MULTIDAM23D.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
ITYPE 545
COMMNT Any comment (up to 60 characters) that will be reproduced on the output listing

Integer parameters

Line 1 (7I5)
NINTV Number of sub-steps used to integrate numerically the constitutive equation in a time step
NPOINT = 2 : (Bilinear evolution of the EVP law) or more (multilinear evolution)
IVISC = 1 for EVP law
≠ 1 for EP law
MMATE = 1 : Brittle material
≠ 1 : Ductile material
MNINTV Maximum of number of sub-steps (0$\rightarrow$100)
MITERA Number of sub-iteration (0$\rightarrow$10) in the plastic and damage correction loop
MUTIP Number of multiplicator for sub-steps (0$\rightarrow$2), when strain variation is found too big, the limit is Deltamin

Real parameters

Line 1 (4G10.0)
ECROU = 0 : Isotropic hardening
= 1 : Cinematic hardening
$\in$ [0,1] : Mixed hardening 
DMMAX = 0 : EP without damage
$\in$ [0,1] : maximum damage value at initial fracture
Otherwise : 0.95 limit damage value
PROC Precision of iteration (= 0$\rightarrow$1.D-3)
DELTAMIN Maximum of the permitted equivalent strain increment
Necessary because of instability in damage resolution
Line 2 - Only if IANA ≠ 4 (2D state) (G10.0)
THICK Thickness for plane state 
Line 2 or 3 (G10.0)
VISCO Viscosity parameter (unit : time) 

Material parameters

Line 1 (3G10.0)
ANU12 POISSON’s ratio in 1-2 plane
ANU23 POISSON’s ratio in 2-3 plane
ANU13 POISSON’s ratio in 1-3 plane
Line 2 (6G10.0)
EPSY1 Initial elastic strain limit of uniaxial tension in 1 direction
EPSY2 Initial elastic strain limit of uniaxial tension in 2 direction
EPSY3 Initial elastic strain limit of uniaxial tension in 3 direction
EPSY12 Initial elastic strain limit in 1-2 plane
EPSY23 Initial elastic strain limit in 2-3 plane
EPSY13 Initial elastic strain limit of 1-3 plane
Line 3 (6G10.0)
SIGY1 Yield limit of uniaxial tension in 1 direction
SIGY2 Yield limit of uniaxial tension in 2 direction
SIGY3 Yield limit of uniaxial tension in 3 direction
SIGY12 Yield limit in 1-2 plane
SIGY23 Yield limit in 2-3 plane
SIGY13 Yield limit in 1-3 plane

Effective stress-strain curves

To repeat NPOINT-1 times :

Line 1 (6G10.0)
EPS1 Strain by uniaxial testing in 1 direction
EPS2 Strain by uniaxial testing in 2 direction
EPS3 Strain by uniaxial testing in 3 direction
EPS12 Strain by testing in plane 1-2
EPS23 Strain by testing in plane 2-3
EPS12 Strain by testing in plane 1-3
Line 2 (6G10.0)
SIG1 Stress by uniaxial testing in 1 direction
SIG2 Stress by uniaxial testing in 2 direction
SIG3 Stress by uniaxial testing in 3 direction
SIG12 Stress by testing in 1-2 plane
SIG23 Stress by testing in 2-3 plane
SIG13 Stress by testing in 1-3 plane

Damage parameters

Line 1 (6G10.0)
RD01 Initial damage limit in 1 direction
RD02 Initial damage limit in 2 direction
RD03 Initial damage limit in 3 direction
DT1 Damage tangent modulus in 1 direction
DT2 Damage tangent modulus in 2 direction
DT3 Damage tangent modulus in 3 direction

Stresses

Number of stresses

6 for 3D state
4 for the other cases

Meaning

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

For the 3-D state:

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

For the other cases:

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

State variables

Number of state variables

= 32 for 3D state
= 30 for the other cases

List of state variables

N = 32 for 3D state
N = 30 for the other cases.

Q(1) Element thickness ($t$) in plane stress state
= 1 : Plane strain state
Circumferential strain rate ($\dot{\varepsilon}_{\theta}$) in axisymmetrical state
= 0 : 3D state
Q(2) = 0 : Current state is elastic
= 1 : Current state is elasto-plastic
Q(3) = 0 : Current state is not damaged
= 1 : Current state is damaged
Q(4) Equivalent plastic strain ($\varepsilon_{eq}$)
Q(5) Equivalent damage ($d_{eq}$)
Q(6) Plastic hardening level ($R$)
Q(7) Damage hardening level ($B$)
Q(8) Damage in 1 direction of material ($D_1$)
Q(9) Damage in 2 direction of material ($D_2$)
Q(10) Damage in 3 direction of material ($D_3$)
Q(11) Equivalent stress ($\sigma_{eq}$)
Q(12) Plastic work per unit volume ($W_p$)
Q(13) Damage work per unit volume ($W_d$)
Q(14) Total strain energy per unit volume ($W_t$) (elastic + plastic + damage)
Q(15)$\rightarrow$Q(20) Fracture criteria (computed with the real stress-strain evolution)
Q(21)$\rightarrow$Q(26) Strain values at the integration points (x ,y, z, xy,yz and yz directions)
Q(27)$\rightarrow$Q(N) Back stresses for kinematic and mixed hardening
laws/multidam23d.txt · Last modified: 2020/08/25 15:46 (external edit)