All user function to modify fkm nonlinear constants

Signed-off-by: Benjamin Maier <[email protected]>

Author: maierbn

Diff for: src/pylife/strength/fkm_nonlinear/constants.py

@@ -147,12 +147,15 @@ def for_material_group(assessment_parameters):
         All constants that are defined by FKM nonlinear for the given material group.
 
     """
+    # call user hook to modify constants if necessary
+    global all_constants
+    if "user_hook" in assessment_parameters:
+        all_constants = assessment_parameters["user_hook"](all_constants)
 
     # select set of constants according to given material group
     assert "MatGroupFKM" in assessment_parameters
 
     material_group = assessment_parameters["MatGroupFKM"]
-    assert material_group in ["Steel", "SteelCast", "Al_wrought"]
 
     resulting_constants = all_constants[material_group]
 

Diff for: tests/strength/fkm_nonlinear/test_fkm_nonlinear.py

@@ -23,6 +23,7 @@
 import numpy.testing as testing
 import pylife
 import pylife.strength.fkm_nonlinear
+import pylife.strength.fkm_nonlinear.constants
 import pylife.strength.fkm_nonlinear.parameter_calculations
 import pylife.strength.fkm_nonlinear.parameter_calculations as parameter_calculations
 
@@ -101,6 +102,55 @@ def test_material_constants():
     pd.testing.assert_series_equal(df_to_test.loc["b_M",:], df_reference.loc["b_M",["Steel", "SteelCast", "Al_wrought"]], check_names=False)
 
 
+def test_material_constants_existing_material():
+    assessment_parameters = {
+        "MatGroupFKM": "Al_wrought",
+    }
+    constants = pylife.strength.fkm_nonlinear.constants.for_material_group(assessment_parameters=assessment_parameters)
+    assert constants["E"] == 70e3
+
+
+def test_material_constants_unknown_material_fails():
+    assessment_parameters = {
+        "MatGroupFKM": "new_material",
+    }
+    with pytest.raises(KeyError, match="new_material"):
+        pylife.strength.fkm_nonlinear.constants.for_material_group(assessment_parameters=assessment_parameters)
+
+
+def test_material_constants_new_material():
+
+    # define user function to extend the parameter set
+    def add_new_material(constants):
+        
+        if "new_material" in constants:
+            return constants
+        
+        new_material_constants = pd.DataFrame({
+            "new_material": {
+                "E": 99e3,
+                "n_prime": 0.123,
+            }
+        })
+        return pd.concat([constants, new_material_constants], axis="columns")
+    
+    # add user function
+    assessment_parameters = {
+        "MatGroupFKM": "new_material",
+        "user_hook": add_new_material
+    }
+
+    # retrieve constants
+    constants = pylife.strength.fkm_nonlinear.constants.for_material_group(assessment_parameters=assessment_parameters)
+
+    assert constants["E"] == 99e3
+    assert constants["n_prime"] == 0.123
+
+    # constants are now also updated directly in the module
+    assert "new_material" in pylife.strength.fkm_nonlinear.constants.all_constants
+    assert pylife.strength.fkm_nonlinear.constants.all_constants["new_material"]["E"] == 99e3
+
+
 def test_computation_functions_1():
     """Example 2.10.2, "Welle mit V-Kerbe", p.138 """