Table of Contents
MWAT3
Description
Coupled mechanical-3 flows analysis; Coupling: Mechanical-Water-Air-Temperature in large deformations.
The element is defined by 4, 8, 16, 20, 24 or 32 nodes specified in NODES following the order indicated in the figure.
The constitutive “fluid” laws that can be used with this element are:
Type: 225
Implemented by: J-P. Radu (2000)
Files
Prepro: MWAT3A.F
Lagamine: MWAT3B.F
Input file
| Title (A5) | |
|---|---|
| TITLE | “MWAT3” in the first 5 columns |
| Control data (4I5) | |
| NELEM | Number of elements |
| ISPSMAS | = 0 → nothing = 1 → specific weight taken into account if and only if NTANA < 0 |
| INSIG | = 0 → No initial stress = 1 or 2 → Initial stresses |
| INBIO | = 0 → No Biot coefficient = 1 → Isotropic Biot coefficient = 2 → Anisotropic Biot coefficient Only for orthotropic mechanical law ORTHOPLA |
| Specific mass - Only if ISPMAS = 1 (1G10.0) | |
| SPEMA5 | Specific mass |
| Initial stresses - Only if INSIG > 0 (4G10.0) | |
| If INSIG=1: $\sigma_z=\sigma_{z0}+zd\sigma_{z}$ If INSIG=2: $\sigma_z=min(\sigma_{z0}+zd\sigma_z,0)$ |
|
| SIGZ0 | $\sigma_{y0}$ effective stress $\sigma_y$ at the axes origin |
| DSIGZ | Effective stress gradient along Y axis |
| AK0X | $k_0$ ratio $\sigma_x/\sigma_z$ |
| AK0Y | $k_0$ ratio $\sigma_y/\sigma_z$ (if AK0Y=0, AK0Y=AK0X) |
| In the calculation of SIGZ0 and DSIGZ, the apparent density $\rho_a'$ must be taken into consideration: \[\rho_a'=\left[(1-n)\rho_s+n S_w\rho_w\right]-\rho_w\] With: $\rho_s$ the solid density (this corresponds to the density of a fictive sample where porosity would be equal to zero) $\rho_w$ the density of the fluid $n$ the porosity defined in the flow law related to this element $S_w$ the fluid saturation, ∈ [0,1] |
|
| Biot coefficient - Only if INBIO = 1 (1G10.0) | |
| CBIOT | Biot coefficient |
| Definition of the elements (6I5/14I5) | |
| NNODE | Number of nodes of the brick: 8, 16, 20, 24, 32, or 4 for the tetrahedron |
| NPI(1) | Number of integration points in each direction For the tetrahedron with 1 I.P., NPI(1)=1 and NPI(2)=NPI(3)=0 For the tetrahedron with 4 I.P., NPI(1)=4 and NPI(2)=NPI(3)=0 |
| NPI(2) | |
| NPI(3) | |
| LMAT1 | Mechanical law |
| LMAT2 | Flow law |
| NODES | List of nodes |
Results
Stresses (in global axes)
- Mechanical stresses: $\sigma_x,\sigma_y,\sigma_z,\sigma_{xy},\sigma_{xz},\sigma_{yz}$
- Water flow: $f_{wx},f_{wy},f_{wz},f_{w,stored}$
- Air flow: $f_{ax},f_{ay},f_{az},f_{a,stored}$
- Thermal flow: $f_{tx},f_{ty},f_{tz},f_{capacitif}$
Internal variables
Internal variables of the mechanical law
Internal variables of the fluid law