Table of Contents
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) | |
|---|---|
| IL | Law 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 |