Add example cycles_to_failure from McMunich (#591)

* Functioning cyclic_to_failure examples

* Update style

* Add test_examples::test_download_cycles_to_failure

* Comments from Jenna

Signed-off-by: paul.profizi <[email protected]>

* Update title of the example

* Apply suggestions from code review

* Remove section separation for a visually better example

* Rework formatting of the explanation paragraph

* Update examples/02-modal-harmonic/06-cycles_to_failure.py

* Fix formatting of the description

* Fix formatting of the description

* Revert "Remove section separation for a visually better example"

This reverts commit 52d1b1d.

* Reformat sections

* Reformat

* Reformat

* Reformat

* Reformat

* Reformat

* Apply suggestions from code review

Signed-off-by: paul.profizi <[email protected]>

Author: PProfizi

ansys/dpf/core/examples/downloads.py

@@ -79,8 +79,8 @@ def download_transient_result(should_upload: bool = True, server=None,
                               return_local_path=False) -> str:
     """Download an example transient result file and return the download path
     available server side.
-    If the server is remote (or doesn't share the memory), the file is uploaded or made available
-    server side.
+    If the server is remote (or doesn't share memory), the file is uploaded or made available
+    on the server side.
 
     Examples files are downloaded to a persistent cache to avoid
     re-downloading the same file twice.
@@ -118,8 +118,8 @@ def download_all_kinds_of_complexity(should_upload: bool = True, server=None
                                      , return_local_path=False) -> str:
     """Download an example static result and return the download path
     available server side.
-    If the server is remote (or doesn't share the memory), the file is uploaded or made available
-    server side.
+    If the server is remote (or doesn't share memory), the file is uploaded or made available
+    on the server side.
 
     Examples files are downloaded to a persistent cache to avoid
     re-downloading the same file twice.
@@ -158,8 +158,8 @@ def download_all_kinds_of_complexity_modal(should_upload: bool = True, server=No
                                            return_local_path=False) -> str:
     """Download an example result file from a static modal analysis and
     return the download path available server side.
-    If the server is remote (or doesn't share the memory), the file is uploaded or made available
-    server side.
+    If the server is remote (or doesn't share memory), the file is uploaded or made available
+    on the server side.
 
     Examples files are downloaded to a persistent cache to avoid
     re-downloading the same file twice.
@@ -197,8 +197,8 @@ def download_all_kinds_of_complexity_modal(should_upload: bool = True, server=No
 def download_pontoon(should_upload: bool = True, server=None, return_local_path=False) -> str:
     """Download an example result file from a static modal analsys and
     return the download path available server side.
-    If the server is remote (or doesn't share the memory), the file is uploaded or made available
-    server side.
+    If the server is remote (or doesn't share memory), the file is uploaded or made available
+    on the server side.
 
     Examples files are downloaded to a persistent cache to avoid
     re-downloading the same file twice.
@@ -236,8 +236,8 @@ def download_multi_harmonic_result(should_upload: bool = True, server=None,
                                    return_local_path=False) -> str:
     """Download an example multi-harmonic result file and return the
     download path available server side.
-    If the server is remote (or doesn't share the memory), the file is uploaded or made available
-    server side.
+    If the server is remote (or doesn't share memory), the file is uploaded or made available
+    on the server side.
 
     Examples files are downloaded to a persistent cache to avoid
     re-downloading the same file twice.
@@ -273,10 +273,10 @@ def download_multi_harmonic_result(should_upload: bool = True, server=None,
 
 def download_multi_stage_cyclic_result(should_upload: bool = True, server=None,
                                        return_local_path=False) -> str:
-    """Download an example multi stage result file and return the
+    """Download an example multi-stage result file and return the
     download path available server side.
-    If the server is remote (or doesn't share the memory), the file is uploaded or made available
-    server side.
+    If the server is remote (or doesn't share memory), the file is uploaded or made available
+    on the server side.
 
     Examples files are downloaded to a persistent cache to avoid
     re-downloading the same file twice.
@@ -313,8 +313,8 @@ def download_multi_stage_cyclic_result(should_upload: bool = True, server=None,
 def download_sub_file(should_upload: bool = True, server=None, return_local_path=False) -> str:
     """Download an example .sub result file containing matrices and return the
     download path available server side.
-    If the server is remote (or doesn't share the memory), the file is uploaded or made available
-    server side.
+    If the server is remote (or doesn't share memory), the file is uploaded or made available
+    on the server side.
 
     Examples files are downloaded to a persistent cache to avoid
     re-downloading the same file twice.
@@ -352,8 +352,8 @@ def download_msup_files_to_dict(should_upload: bool = True, server=None,
                                 return_local_path=False) -> dict:
     """Download all the files necessary for a msup expansion and return the
     download paths available server side into a dictionary extension->path.
-    If the server is remote (or doesn't share the memory), the files are uploaded or made available
-    server side.
+    If the server is remote (or doesn't share memory), the file is uploaded or made available
+    on the server side.
 
     Examples files are downloaded to a persistent cache to avoid
     re-downloading the same file twice.
@@ -397,8 +397,8 @@ def download_distributed_files(should_upload: bool = True, server=None,
                                return_local_path=False) -> dict:
     """Download distributed rst files and return the
     download paths into a dictionary domain id->path.
-    If the server is remote (or doesn't share the memory), the files are uploaded or made available
-    server side.
+    If the server is remote (or doesn't share memory), the file is uploaded or made available
+    on the server side.
 
     Examples files are downloaded to a persistent cache to avoid
     re-downloading the same file twice.
@@ -439,8 +439,8 @@ def download_distributed_files(should_upload: bool = True, server=None,
 def download_fluent_files(should_upload: bool = True, server=None, return_local_path=False) -> dict:
     """Download the cas and dat file of a fluent analysis and return the
     download paths into a dictionary extension->path.
-    If the server is remote (or doesn't share the memory), the files are uploaded or made available
-    server side.
+    If the server is remote (or doesn't share memory), the file is uploaded or made available
+    on the server side.
 
     Examples files are downloaded to a persistent cache to avoid
     re-downloading the same file twice.
@@ -481,9 +481,9 @@ def download_fluent_files(should_upload: bool = True, server=None, return_local_
 def download_extrapolation_3d_result(should_upload: bool = True, server=None,
                                      return_local_path=False) -> dict:
     """Download example static results of reference and integrated points
-    for extrapolation of 3d-element and return return the dictionary of 2 download paths.
-    If the server is remote (or doesn't share the memory), the files are uploaded or made available
-    server side.
+    for extrapolation of 3d-element and return the dictionary of 2 download paths.
+    If the server is remote (or doesn't share memory), the file is uploaded or made available
+    on the server side.
 
     Examples files are downloaded to a persistent cache to avoid
     re-downloading the same file twice.
@@ -532,8 +532,8 @@ def download_extrapolation_2d_result(should_upload: bool = True, server=None,
                                      return_local_path=False) -> dict:
     """Download example static results of reference and integrated points
     for extrapolation of 2d-element and return the dictionary of 2 download paths.
-    If the server is remote (or doesn't share the memory), the files are uploaded or made available
-    server side.
+    If the server is remote (or doesn't share memory), the file is uploaded or made available
+    on the server side.
 
     Examples files are downloaded to a persistent cache to avoid
     re-downloading the same file twice.
@@ -581,8 +581,8 @@ def download_extrapolation_2d_result(should_upload: bool = True, server=None,
 def download_hemisphere(should_upload: bool = True, server=None, return_local_path=False) -> str:
     """Download an example result file from a static analysis and
     return the download path available server side.
-    If the server is remote (or doesn't share the memory), the file is uploaded or made available
-    server side.
+    If the server is remote (or doesn't share memory), the file is uploaded or made available
+    on the server side.
 
     Examples files are downloaded to a persistent cache to avoid
     re-downloading the same file twice.
@@ -620,8 +620,8 @@ def download_example_asme_result(should_upload: bool = True, server=None,
                                  return_local_path=False) -> str:
     """Download an example result file from a static analysis and
     return the download path available server side.
-    If the server is remote (or doesn't share the memory), the file is uploaded or made available
-    server side.
+    If the server is remote (or doesn't share memory), the file is uploaded or made available
+    on the server side.
 
     Examples files are downloaded to a persistent cache to avoid
     re-downloading the same file twice.
@@ -657,8 +657,8 @@ def download_example_asme_result(should_upload: bool = True, server=None,
 def download_crankshaft(should_upload: bool = True, server=None, return_local_path=False) -> str:
     """Download the result file of an example of a crankshaft
     under load and return the download path available server side.
-    If the server is remote (or doesn't share the memory), the file is uploaded or made available
-    server side.
+    If the server is remote (or doesn't share memory), the file is uploaded or made available
+    on the server side.
 
     Examples files are downloaded to a persistent cache to avoid
     re-downloading the same file twice.
@@ -695,8 +695,8 @@ def download_crankshaft(should_upload: bool = True, server=None, return_local_pa
 def download_piston_rod(should_upload: bool = True, server=None, return_local_path=False) -> str:
     """Download the result file of an example of a piston rod
     under load and return the download path available server side.
-    If the server is remote (or doesn't share the memory), the file is uploaded or made available
-    server side.
+    If the server is remote (or doesn't share memory), the file is uploaded or made available
+    on the server side.
 
     Examples files are downloaded to a persistent cache to avoid
     re-downloading the same file twice.
@@ -846,3 +846,44 @@ def download_binout_glstat(should_upload: bool = True, server=None, return_local
 
     """
     return _download_file("binout", "binout_glstat", should_upload, server, return_local_path)
+
+
+def download_cycles_to_failure(should_upload: bool = True,
+                               server=None,
+                               return_local_path=False) -> str:
+    """Download an example result file from a cyclic analysis and
+    return the download path.
+    If the server is remote (or doesn't share memory), the file is uploaded or made available
+    on the server side.
+
+    Examples files are downloaded to a persistent cache to avoid
+    re-downloading the same file twice.
+
+    Parameters
+    ----------
+    should_upload : bool, optional (default True)
+        Whether the file should be uploaded server side when the server is remote.
+    server : server.DPFServer, optional
+        Server with channel connected to the remote or local instance. When
+        ``None``, attempts to use the global server.
+    return_local_path: bool, optional
+        If ``True``, the local path is returned as is, without uploading, nor searching
+        for mounted volumes.
+
+    Returns
+    -------
+    str
+        Path to the example file.
+
+    Examples
+    --------
+    Download an example result file and return the path of the file
+
+    >>> from ansys.dpf.core import examples
+    >>> path = examples.download_cycles_to_failure()
+    >>> path
+    'C:/Users/user/AppData/local/temp/cycles_to_failure.rst'
+
+    """
+    return _download_file("cyclic", "cyclic_to_failure.rst",
+                          should_upload, server, return_local_path)

examples/02-modal-harmonic/06-cycles_to_failure.py

@@ -0,0 +1,124 @@
+"""
+.. _ref_cycles_to_failure:
+
+Calculate the number of cycles to fatigue failure
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+This example shows how to generate and use a result file to calculate the
+cycles to failure result for a simple model.
+
+Material data is manually imported, Structural Steel from Ansys Mechanical:
+
+- Youngs Modulus (youngsSteel)
+- Poisson's Ratio (prxySteel)
+- SN curve (sn_data)
+
+The first step is to generate a simple model with high stress and save the
+results .rst file locally to myDir (default is "C:\\\\temp").
+For this, we provide a short pyMAPDL script.
+
+.. line-block::
+  The second step uses PyDPF-Core to generate the cycles to failure result:
+  The locally saved .rst file is imported and plotted.
+  Then the von Mises stress is generated and plotted with DPF operators.
+  The NumPy python package is then used to interpolate the cycles to failure values.
+  The nodal von Mises equivalent stress value is used in the interpolation.
+  (Note that the cycles to failure data must be manipulated to use NumPy interpolation)
+  An empty field is then created and filled with the resulting cycles to failure values.
+  The cycles to failure result is finally plotted.
+
+The cycles to failure result is the (interpolated) negative of the stress result.
+The higher the stress result, the lower the number of cycles to failure.
+"""
+
+from ansys.dpf import core as dpf
+from ansys.dpf.core import examples
+import numpy as np
+
+###############################################################################
+# The first step is to generate a simple model with high stress
+
+# # Material parameters from Ansys Mechanical Structural Steel
+youngsSteel = 200e9
+prxySteel = 0.3
+sn_data = np.empty((11, 2))  # initialize empty np matrix
+sn_data[:, 0] = [10, 20, 50, 100, 200, 2000, 10000, 20000, 1e5, 2e5, 1e6]
+sn_data[:, 1] = [3.999e9, 2.8327e9, 1.896e9, 1.413e9, 1.069e9, 4.41e8, 2.62e8, 2.14e8, 1.38e8,
+                 1.14e8, 8.62e7]
+
+###############################################################################
+# The .rst file used is already available, but can be obtained using the short pyMAPDL code below:
+
+# # ### Launch pymapdl to generate rst file in myDir
+# from ansys.mapdl.core import launch_mapdl
+# import os
+#
+#
+# mapdl = launch_mapdl()
+# mapdl.prep7()
+# # Model
+# mapdl.cylind(0.5, 0, 10, 0)
+# mapdl.mp("EX", 1, youngsSteel)
+# mapdl.mp("PRXY", 1, prxySteel)
+# mapdl.mshape(key=1, dimension='3d')
+# mapdl.et(1, "SOLID186")
+# mapdl.esize(0.3)
+# mapdl.vmesh('ALL')
+#
+# # #### Boundary Conditions: fixed constraint
+# mapdl.nsel(type_='S', item='LOC', comp='Z', vmin=0)
+# mapdl.d("all", "all")
+# mapdl.nsel(type_='S', item='LOC', comp='Z', vmin=10)
+# nnodes = mapdl.get("NumNodes", "NODE", 0, "COUNT")
+# mapdl.f(node="ALL", lab="fy", value=-13e6 / nnodes)
+# mapdl.allsel()
+#
+# # #### Solve
+# mapdl.run("/SOLU")
+# sol_output = mapdl.solve()
+# rst = os.path.join(mapdl.directory, 'file.rst')
+# mapdl.exit()
+# print('apdl model solved.')
+
+###############################################################################
+# PyDPF-Core is then used to post-process the .rst file to estimate the cycles to failure.
+
+# Comment the following line if solving the MAPDL problem first.
+rst = examples.download_cycles_to_failure()
+
+# Import the result as a DPF Model object.
+model = dpf.Model(rst)
+print(model)
+
+###############################################################################
+# Get the von mises equivalent stress, requires an operator.
+s_eqv_op = dpf.operators.result.stress_von_mises(data_sources=model)
+vm_stress_fc = s_eqv_op.eval()
+vm_stress_field = vm_stress_fc[0]
+vm_stress_field.plot(text="VM stress field")
+
+###############################################################################
+# Use NumPy to interpolate the results.
+
+# Inverse the sn_data
+x_values = sn_data[:, 1][::-1]  # the x values are the stress ranges in ascending order
+y_values = sn_data[:, 0][::-1]  # y values are inverted cycles to failure
+
+# Interpolate cycles to failure for the VM values
+cycles_to_failure = np.interp(vm_stress_field.data, x_values, y_values)
+
+###############################################################################
+# Generate a cycles_to_failure DPF Field
+
+# Create an empty field
+cycles_to_failure_field = dpf.Field(nentities=len(vm_stress_field.scoping),
+                                    nature=dpf.natures.scalar,
+                                    location=dpf.locations.nodal)
+# Populate the field
+cycles_to_failure_field.scoping = vm_stress_field.scoping
+cycles_to_failure_field.meshed_region = vm_stress_field.meshed_region
+cycles_to_failure_field.data = cycles_to_failure
+
+# Plot the field
+sargs = dict(title="cycles", fmt="%.2e")
+cycles_to_failure_field.plot(text="Cycles to failure", scalar_bar_args=sargs)

tests/test_examples.py

@@ -34,6 +34,11 @@ def test_download_piston_rod():
     assert isinstance(Model(path), Model)
 
 
+def test_download_cycles_to_failure():
+    path = examples.download_cycles_to_failure()
+    assert isinstance(Model(path), Model)
+
+
 list_examples = [
     "simple_bar",
     "static_rst",