ogstools.propertylib.mesh_dependent module

Functions related to stress analysis which can be only applied to a mesh.

ogstools.propertylib.mesh_dependent.depth(mesh, use_coords=False)

Return the depth values of the mesh.

For 2D, the last axis of the plane wherein the mesh is lying is used as the vertical axis (i.e. y if the mesh is in the xy-plane, z if it is in the xz-plane), for 3D, the z-axes is used. If use_coords is True, returns the negative coordinate value of the vertical axis. Otherwise, the vertical distance to the top facing edges / surfaces are returned.

Parameters:

• mesh (UnstructuredGrid)

• use_coords (bool)

Return type:

ndarray

ogstools.propertylib.mesh_dependent.p_fluid(mesh)

Return the fluid pressure in the mesh.

If “depth” is given in the mesh’s point _data, it is used return a hypothetical water column defined as:

\[p_{fl} = 1000 \frac{kg}{m^3} 9.81 \frac{m}{s^2} h\]

where h is the depth below surface. Otherwise, If “pressure” is given in the mesh, return the “pressure” data of the mesh. If that is also not the case, the hypothetical water column from above is returned with the depth being calculated via ogstools.propertylib.mesh_dependent.depth().

Parameters:

mesh (UnstructuredGrid)

Return type:

PlainQuantity

ogstools.propertylib.mesh_dependent.fluid_pressure_criterion(mesh, mesh_property)

Return the fluid pressure criterion.

Defined as the difference between fluid pressure and minimal principal stress (compression positive).

\[F_{p} = p_{fl} - \sigma_{min}\]

Fluid pressure is evaluated via ogstools.propertylib.mesh_dependent.p_fluid().

Parameters:

• mesh (UnstructuredGrid)

• mesh_property (Property)

Return type:

PlainQuantity

ogstools.propertylib.mesh_dependent.dilatancy_critescu(mesh, mesh_property, a=-0.01697, b=0.8996, effective=False)

Return the dilatancy criterion defined as:

\[F_{dil} = \frac{\tau_{oct}}{\sigma_0} - a \left( \frac{\sigma_m}{\sigma_0} \right)^2 - b \frac{\sigma_m}{\sigma_0}\]

for total stresses and defined as:

\[F'_{dil} = \frac{\tau_{oct}}{\sigma_0} - a \left( \frac{\sigma'_m}{\sigma_0} \right)^2 - b \frac{\sigma'_m}{\sigma_0}\]

for effective stresses (uses p_fluid()).

<https://www.sciencedirect.com/science/article/pii/S0360544222000512?via%3Dihub>

Parameters:

• mesh (UnstructuredGrid)

• mesh_property (Property)

• a (float)

• b (float)

• effective (bool)

Return type:

PlainQuantity

ogstools.propertylib.mesh_dependent.dilatancy_alkan(mesh, mesh_property, b=0.04, effective=False)

Return the dilatancy criterion defined as:

\[F_{dil} = \tau_{oct} - \tau_{max} \cdot b \frac{\sigma'_m}{\sigma_0 + b \cdot \sigma'_m}\]

for total stresses and defined as:

\[F_{dil} = \tau_{oct} - \tau_{max} \cdot b \frac{\sigma'_m}{\sigma_0 + b \cdot \sigma'_m}\]

for effective stresses (uses p_fluid()).

<https://www.sciencedirect.com/science/article/pii/S1365160906000979>

Parameters:

• mesh (UnstructuredGrid)

• mesh_property (Property)

• b (float)

• effective (bool)

Return type:

PlainQuantity | ndarray