[propertylib] new example for stress analysis

docs/examples/howto_meshplotlib/plot_solid_mechanics.py

+"""
+Stress analysis
+===============
+
+.. sectionauthor:: Florian Zill (Helmholtz Centre for Environmental Research GmbH - UFZ)
+
+The following example from the ogs benchmark collection is used for the
+stress analysis:
+
+<https://www.opengeosys.org/docs/benchmarks/thermo-mechanics/creepafterexcavation/>
+
+
+"""
+
+# %%
+
+# sphinx_gallery_start_ignore
+
+# sphinx_gallery_thumbnail_number = -1
+
+# sphinx_gallery_end_ignore
+
+
+from ogstools.meshplotlib import examples, plot, setup
+from ogstools.meshplotlib.plot_features import plot_streamlines
+from ogstools.propertylib import presets
+
+setup.reset()
+setup.length.output_unit = "km"
+mesh = examples.mesh_mechanics
+fig = plot(mesh, presets.displacement)
+
+# %% [markdown]
+# Tensor components
+# -----------------
+# We can inspect the stress (or strain) tensor components by indexing.
+
+# %%
+fig = plot(mesh, presets.stress["xx"])
+fig = plot(mesh, presets.stress["xy"])
+
+# %% [markdown]
+# Principal stresses
+# ------------------
+# Let's calculate the the principal stress components and overlay the direcetion
+# of the corresponding eigenvector. Note: the eigenvalues are sorted by
+# increasing order, i.e. eigenvalue[0] is the most negative / largest
+# compressive principal stress.
+
+# %%
+eigvecs = presets.stress.eigenvectors
+fig = plot(mesh, mesh_property=presets.stress.eigenvalues[0])
+plot_streamlines(ax=fig.axes[0], mesh=mesh, property=eigvecs[0], arrows=True)
+
+# %%
+fig = plot(mesh, mesh_property=presets.stress.eigenvalues[1])
+plot_streamlines(ax=fig.axes[0], mesh=mesh, property=eigvecs[1], arrows=True)
+
+# %%
+fig = plot(mesh, mesh_property=presets.stress.eigenvalues[2])
+plot_streamlines(ax=fig.axes[0], mesh=mesh, property=eigvecs[2], arrows=True)
+
+# %% [markdown]
+# We can also plot the mean of the principal stress, i.e. the magnitude of the
+# hydrostatic component of the stress tensor.
+# see: :py:func:`ogstools.propertylib.tensor_math.mean`
+
+# %%
+fig = plot(mesh, presets.stress.mean)
+
+# %% [markdown]
+# Von Mises stress
+# ----------------
+# see: :py:func:`ogstools.propertylib.tensor_math.von_mises`
+
+# %%
+fig = plot(mesh, presets.stress.von_Mises)
+
+# %% [markdown]
+# octahedral shear stress
+# -----------------------
+# see: :py:func:`ogstools.propertylib.tensor_math.octahedral_shear`
+
+# %%
+fig = plot(mesh, presets.stress.octahedral_shear)
+
+# %% [markdown]
+# Integrity criteria
+# ==================
+# Evaluate models regarding their integrity is often dependent on the geometry,
+# e.g. for a hypothetical water column proportional to the depth. Presets which
+# fall under this category make use of
+# :py:mod:`ogstools.propertylib.mesh_dependent`.
+
+# %% [markdown]
+# Dilantancy criterion
+# --------------------
+# see: :py:func:`ogstools.propertylib.mesh_dependent.dilatancy_critescu`
+
+# %%
+fig = plot(mesh, presets.dilatancy_critescu)
+fig = plot(mesh, presets.dilatancy_critescu_eff)
+
+# %% [markdown]
+# Fluid pressure criterion
+# ------------------------
+# see: :py:func:`ogstools.propertylib.mesh_dependent.fluid_pressure_criterion`
+
+# %%
+fig = plot(mesh, presets.fluid_pressure_crit)

ogstools/meshplotlib/examples/__init__.py

+import pyvista as pv
+
 from ogstools.definitions import ROOT_DIR
 from ogstools.meshlib import MeshSeries
 
@@ -9,3 +11,6 @@ meshseries_XDMF = MeshSeries(
     str(examples / "2D_single_fracture_HT_2D_single_fracture.xdmf"),
     time_unit="s",
 )
+mesh_mechanics = pv.XMLUnstructuredGridReader(
+    str(examples / "mechanics_example.vtu")
+).read()