Material manager
The material manager is where continuum materials are defined. It replaces the former Materials branch of the data tree, which is no longer available.
Open it from the numgeo tools toolbar, from numgeo → Manager → Material, or from the Assign material branch of the data tree when picking a material for an entity.
How materials are stored
Material definitions are held in a database file, numgeo_materials.tcldata,
which is written next to the GiD project. The data tree receives only the
material name, which is what gets assigned to surfaces and volumes.
When the input files are generated, the definitions are written to
material-definitions.inp.
Two consequences are worth remembering:
- The database follows the project automatically on Save as, but if a project
is copied or sent by hand,
numgeo_materials.tcldatamust be copied with it. Without it the material names in the tree have no definitions behind them. - Renaming a material in the manager does not update assignments that already reference the old name. Re-assign the affected entities afterwards.
Window layout
The window is split into a material list on the left and an editor on the right.
The list shows every material in the project together with its mechanical model. Three buttons underneath it act on whole materials:
| Button | Action |
|---|---|
| New | Create a material with a unique default name |
| Duplicate | Copy the selected material, including all parameters |
| Delete | Remove the selected material, after confirmation |
The buttons along the bottom of the window act on the session:
| Button | Action |
|---|---|
| Apply & Save | Validate the current form, store it and write the database |
| Close | Close the manager, prompting first if there are unsaved changes |
| Use selected material | Close the manager and return the selected name for assignment |
Use selected material only appears when the manager was opened from the data tree in order to pick a material.
The editor on the right is a set of tabs. Which tabs and which rows are visible depends on the number of phases set for the material, so it is best to set the phase count first.
Number of phases
Materials are single-, two- or three-phase:
| Phases | Meaning | Effect on the editor |
|---|---|---|
| 1 | Dry solid skeleton | Permeability and hydraulic tabs are hidden |
| 2 | Solid + water | Permeability tab and Kw become available |
| 3 | Solid + water + air | Hydraulic, relative permeability and Bishop settings become available |
Changing the phase count shows and hides the dependent rows immediately.
Tabs
Phase properties
One density entry per active phase — phase 1 (solid), phase 2 (water), phase 3 (air), each in g/cm³. Every active phase must be filled.
Bulk modulus of the fluid phases: Kw for water at two or more phases,
Ka for air at three phases, both in kPa. The section is hidden entirely for
single-phase materials.
Mechanical
The constitutive model of the solid skeleton. The parameter fields, their number and their layout change with the model:
| Group | Models |
|---|---|
| Elastic | Linear Elasticity, Barotropic elasticity, Bathytropic Elasticity, Neo Hooke-2 |
| Failure-criterion based | Mohr-Coulomb, Mohr-Coulomb-2, Mohr-Coulomb-3, Matsuoka-Nakai |
| Critical-state | Modified-Cam-Clay, Sanisand |
| Hardening | Hardening-Soil, Hardening-Soil-Bricks |
| Hypoplastic | Hypoplasticity, Hypoplastic+IGS-2, Hypoplasticity+ISA, Hypoplasticity+ISA-SF, Hypoplastic+GIS, AVHP, AVISA |
| High-cycle accumulation | HCA Linear Elasticity, HCA Hypoplasticity, HCA Hypoplasticity+ISA, HCA Sanisand |
| Own implementation | User-defined |
Each model maps to a numgeo keyword, which is filled in automatically but can be overridden. The parameters of every model are listed in Constitutive models.
Permeability
Available for two- and three-phase materials. The tab holds four sections:
Intrinsic permeability — Isotropic (a single value), Kozeny-Carman
(parameters c and de), or User-defined.
Dynamic viscosity — mu_w for water, and mu_a for air at three phases.
Relative permeability — only at three phases. Available relations are
vanGenuchten and Brooks-Corey, each with kw,min, ka,min and n, or
User-defined.
Hydraulic conductivity scale — a read-only display, not an input. It
evaluates the hydraulic conductivity from the intrinsic permeability k, the
water density ρ_w and the dynamic water viscosity μ_w:
The result is placed on the Terzaghi soil-classification bands, so that an
implausible permeability is visible immediately. It updates live as k, ρ_w
or μ_w change.
Hydraulic
Only for three-phase materials: the suction–saturation relation.
| Model | Parameters |
|---|---|
| vanGenuchten | Swr, alpha, n |
| Brooks-Corey | Swr, lambda, p^b |
| Fredlund-Xing | hr, af, nf, mf |
| Exponential model | Swr, zeta |
| Gallipoli model | Swr, phi, psi, m, n |
| User-defined | — |
Each model also carries a Jacobian setting, which defaults to Smoothed.
Bishop
Only for three-phase materials, and a selection is mandatory: the effective-stress
method. Available are Effective-Saturation, Saturation, Crude-Switch,
Lu-Likos and Power-Saturation. Lu-Likos additionally requires kappa and
S^wr; Power-Saturation requires kappa.
Rayleigh damping
Disabled by default. When enabled, damping is specified through two frequencies
f1 and f2 and a damping ratio, from which the coefficients α and β are
computed. A plot shows the resulting damping curve over frequency, so the
behaviour outside the interval [f1, f2] is visible.
f1 and f2 must both be positive with f2 > f1, and the damping ratio must
not be negative.
Stabilization
A set of independent switches, each of which reveals its own parameters:
| Feature | Required when enabled |
|---|---|
| Minimum pressure | the pressure value |
| Mechanical viscosity | model, p_min, p_max, lambda_min, lambda_max, mu_min, mu_max |
| Phantom elasticity | E and nu |
| Hourglass stiffness | method, c_hg, c_fhg |
| FPL stabilisation | alpha_fpl |
Others
An escape hatch for keywords the structured tabs do not cover. Anything typed in the upper text area is appended verbatim to the material definition in the generated input file, so it must be valid numgeo syntax.
The lower Notes area is for your own comments — it is never written to the input file.
Validation
Materials are checked when Apply & Save is pressed, and the first problem found is reported. The rules are:
- The name must not be empty, must not contain a comma, and must consist of letters, digits, underscore, hyphen or dot, starting with a letter or underscore.
- The number of phases must be 1, 2 or 3.
- Every active phase must have a density.
- The mechanical keyword must not be empty, and all model parameters must be present and numeric.
- For two or more phases, a permeability model with valid parameters is required.
- For three phases, a Bishop method must be selected; hydraulic and relative-permeability models are validated only if they have been chosen.
- Rayleigh and stabilisation rules as described above.
Note
The comma rule exists because the data tree receives the material names as a comma-separated list. A comma in a name would split it into two entries.