====== DVREE ======

===== Description =====

Simple damage constitutive law.

==== The model ====

This law is used for mechanical analysis for solids.

==== Files ====

Prepro: LDVREE.F \\
Lagamine: DVREE.F

===== Availability =====

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

===== Input file =====

==== Parameters defining the type of constitutive law ====

^ Line 1 (2I5, 60A1)^^
|IL|Law number|
|ITYPE| 592|
|COMMNT| Any comment (up to 60 characters) that will be reproduced on the output listing|

==== Integer parameters ====

^ Line 1 (3I5) ^^
|NINTV| = 1 (by default) |
|ISOL| = 0 : Use of total stresses in the constitutive law |
|:::|≠ 0 : Use of effective stresses in the constitutive law (see annex 8) |
|ITEMOIN| = 1 : Constitutive matrix computed by perturbation |
|:::| = 0 : Secant matrix |
|:::| = -1 : Analytical tangent matrix |

==== Real parameters ====

^ Line 1 (3G10.0) ^^
|E| YOUNG's elastic modulus |
|ANU| POISSON's ratio |
|FT| Tensile strength |
^ Line 2 (3G10.0) ^^
|ALPHA| 1st parameter controlling the final stress |
|BETA| 2nd parameter controlling the shape of the softening curve |
|ETA| Ratio of the compressive stress limit over the tensile stress limit |
^ Line 3 (2G10.0) ^^
|DIV| Time integration parameter |
|RHOS| Specific mass |

===== Stresses =====

==== Number of stresses ====

4 (2D only)

==== Meaning ====

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

For the 2D state :
|SIG(1)|$\sigma_{xx}$|
|SIG(2)|$\sigma_{yy}$|
|SIG(3)|$\sigma_{xy}$|
|SIG(4)|$\sigma_{zz}$|

===== State variables =====

==== Number of state variables ====

10

==== List of state variables ====

__2D plane strain or axisymmetric analysis :__
|Q(1)| THICK : Thickness (axisymmetric or plane stress state) |
|Q(2)| D : Damage |
|Q(3)| EPSTIL : Equivalent deformation |
|Q(4)| RHOS : Actualised specific mass |
|Q(5)| DXXT : Strain computed at the previous step |
|Q(6)| DYYT : Strain computed at the previous step |
|Q(7)| DZZT : Strain computed at the previous step |
|Q(8)| DXYT : Strain computed at the previous step |
|Q(9)| = 1 : FLAG : Flag for increasing damage |
|:::| = 0 : FLAG : Flag for constant damage |
|Q(10)| EPSD0 damage threshold |