Material manager
The material manager is where continuum materials are defined — the soil and
rock of the model. Sections for truss and beam members are defined separately,
in the 
truss/beam material manager.
Defining a material and using it are two steps: the manager creates the definition, and the Assign material branch of the data tree attaches it to surfaces and volumes.
Open the manager with the 
button in the numgeo toolbar, from numgeo → Manager → Material, or from the
Assign material branch of the data tree when picking a material for an entity.
Window layout
The window is split into the list of defined materials on the left and the material definition on the right.
The Defined materials list shows every material in the project with its mechanical model and its number of phases. Three buttons underneath 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 at the bottom right act on the session:
| Button | Action |
|---|---|
| Apply & Save | Validate the current form and store it |
| 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 appears only when the manager was opened from the data tree in order to pick a material.
Name and number of phases
Two fields sit above the tabs and apply to the whole material.
The Name is what the data tree receives, and it is what gets assigned to surfaces and volumes.
The Number of phases decides how the soil is modelled, and it controls which tabs and which rows are available. Set it before filling in the tabs.
| Phases | Meaning | Effect |
|---|---|---|
| 1 | Dry solid skeleton | Permeability and hydraulic settings are hidden |
| 2 | Solid and water | Permeability model and Kw become available |
| 3 | Solid, water and air | Hydraulic model, relative permeability and Bishop effective stress become available |
Changing the number of phases shows and hides the dependent rows immediately.
Tabs
The material definition is spread over eight tabs:
| Tab | Holds |
|---|---|
| Phase properties | Density of each active phase, and the bulk modulus of the fluid phases |
| Mechanical model | The constitutive model of the solid skeleton and its parameters |
| Permeability model | Intrinsic permeability, dynamic viscosity and relative permeability |
| Hydraulic model | The suction–saturation relation |
| Bishop effective stress | The effective-stress method for unsaturated soil |
| Rayleigh damping | Damping for dynamic analyses |
| Stabilization parameters | Numerical stabilisation options |
| Others | Additional keywords and your own notes |
Materials and the project
Materials belong to the project they were defined in. Use Files → Save as to copy a project, so that its materials travel with it.
Renaming a material does not update assignments that already reference the old name. Re-assign the affected entities afterwards.
Validation
Materials are checked when Apply & Save is pressed, and the first problem found is reported. The general 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 rules that belong to a particular tab are described on that tab's page.
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.