Design Configuration

In this example we will demonstrate: Access the Steel Design add-on ULS and SLS configuration Enable the adapted method for double bending in the ULS configuration, a setting whose parent branch has to be written with it Select Method 2 acc. to Annex B for the interaction factors kyy, kyz, kzy, kzz, a setting that cannot be reached by path Change a deflection limit value in the SLS configuration, a value that cannot be reached by key Apply the updated configuration to the model

Note

Whether a setting is written by key or by path follows from the tree, not from preference:

• a key that is unique in the tree can be set by key

• a key with several occurrences, such as the deflection limit l_, needs the path

• a key whose parent occurs more than once, such as param_k_annex_b under define_parameters_for_lateral_torsional_buckling, cannot be reached by path and has to be set by key

A setting nested under a parent checkbox is only effective once that parent is active as well. Writing the leaf alone stores the value but leaves it without effect, exactly like a greyed-out checkbox in the dialog.

PythonC#

from dlubal.api import rfem, common


# -------------------------------------------------------
# This example demonstrates how to modify a design configuration
# in the model by using helper functions to interact with the
# tree table data structure, either by key or by path.
#
# The settings used here are the ones from the dialog
# "Edit Ultimate Configuration | Steel Design", tab
# "Members | Stability":
#
#   Calculation Method
#     2D - General method (4 degrees of freedom)
#       [x] Extension methods
#           ( ) Interpolation acc. to Eq. 6.66
#           (o) European lateral-torsional buckling curve
#               [x] Adapted method (enable double bending)
#
#   6.3.3(4) Parameters kyy, kyz, kzy, kzz
#     Determine interaction factors for 6.3.3(4) according to
#       ( ) Method 1 acc. to Annex A
#       (o) Method 2 acc. to Annex B
#
# and, from the serviceability configuration, the relative
# deflection limit of a beam.
#
# Which helper to use follows from the tree, not from taste:
#   - a key that is unique in the tree can be set by key
#   - a key with several occurrences needs the path
#   - a key whose PARENT occurs more than once cannot be
#     reached by path and has to be set by key
# All three situations appear below.
# -------------------------------------------------------


def print_tree_table(rows, depth: int = 0) -> None:
    """
    This function prints a tree table recursively, one row per line, with the
    key of the row followed by its value and by the caption that the RFEM
    dialog shows for it.

    It is the quickest way to find the key of a setting: search the printed
    output for the caption you see in the dialog and read off the key next to
    it. Group rows carry no value of their own and print as None.
    """
    for row in rows:
        value = common.get_internal_value(row.value)
        print(f"{'  ' * depth}{row.key} = {value} {row.unit}\t| {row.caption}")
        print_tree_table(row.rows, depth + 1)


# Connect to the RFEM application
with rfem.Application() as rfem_app:

    # --- Initialize the model ---

    # A new model with the Steel Design add-on active already contains the ULS
    # and SLS configuration no. 1, so no configuration is created here.
    rfem_app.close_all_models(save_changes=False)
    rfem_app.create_model(name='steel_design_configurations')

    base_data = rfem_app.get_base_data()
    base_data.addons.steel_design_active = True
    base_data.standards.steel_design_standard = rfem.BaseData.Standards.STEEL_DESIGN_NATIONAL_ANNEX_AND_EDITION_EN_1993_NF_2016_02_STANDARD
    rfem_app.set_base_data(base_data=base_data)


    # --- Get/Set value by key ---

    # Retrieve a design configuration
    steel_uls_config: rfem.steel_design_objects.SteelDesignUlsConfiguration = rfem_app.get_object(
        obj=rfem.steel_design_objects.SteelDesignUlsConfiguration(no=1)
    )

    # Get specific tree table from the configuration
    settings_ec3_uls_tree = steel_uls_config.settings_ec3
    print("\nSTEEL_SETTINGS_EC3_ULS_TREE:")
    print_tree_table(settings_ec3_uls_tree.rows)

    # "Adapted method (enable double bending)" extends the general method acc.
    # to EN 1993-1-1, 6.3.4 to biaxial bending. The checkbox is nested under
    # two parents, and a leaf under an inactive parent is stored but has no
    # effect, exactly like a greyed-out checkbox in the dialog. So the whole
    # branch is written, not the leaf alone.
    double_bending_keys = {
        'extensional_methods': True,                          # Extension methods
        'european_lateral_torsional_buckling_curves': True,   # European lateral-torsional buckling curve
        'interpolation_acc_to_eq_666': False,                 # Interpolation acc. to Eq. 6.66
        'adapted_method': True,                               # Adapted method (enable double bending)
    }

    # Get value/s for the key (there can be multiple occurrences)
    for key in double_bending_keys:
        value = common.tree_table.get_values_by_key(
            tree=settings_ec3_uls_tree,
            key=key
        )
        print(f"{key} (key-based search): {value}")

    # Modify the values from the tree by their keys
    for key, value in double_bending_keys.items():
        common.tree_table.set_values_by_key(
            tree=settings_ec3_uls_tree,
            key=key,
            values=[value]
        )

    # "Method 2 acc. to Annex B" determines the interaction factors kyy, kyz,
    # kzy and kzz acc. to 6.3.3(4). Its own key is unique, but its parent key
    # "define_parameters_for_lateral_torsional_buckling" is shared by two
    # sections of the tree, so a path-based search resolves to the wrong one
    # and returns None. Setting it by key is the reliable way here.
    common.tree_table.set_values_by_key(
        tree=settings_ec3_uls_tree,
        key='param_k_annex_b',
        values=[True]
    )

    # Apply the updated configuration to the model
    rfem_app.update_object(
        obj=rfem.steel_design_objects.SteelDesignUlsConfiguration(
            no=1,
            settings_ec3=settings_ec3_uls_tree
        )
    )

    # Read the settings back to confirm what the model stores. The two radio
    # buttons of a group are mutually exclusive, so "Method 1 acc. to Annex A"
    # is cleared by RFEM itself.
    steel_uls_config = rfem_app.get_object(
        obj=rfem.steel_design_objects.SteelDesignUlsConfiguration(no=1)
    )
    print("\nStability settings after the update:")
    for key in list(double_bending_keys) + ['param_k_annex_a', 'param_k_annex_b']:
        value = common.tree_table.get_values_by_key(
            tree=steel_uls_config.settings_ec3,
            key=key
        )
        print(f"  {key:<44}{value}")


    # --- Get/Set value by path ---

    # Retrieve a design configuration
    steel_sls_config: rfem.steel_design_objects.SteelDesignSlsConfiguration = rfem_app.get_object(
        obj=rfem.steel_design_objects.SteelDesignSlsConfiguration(no=1)
    )

    # Get specific tree table from the configuration
    settings_ec3_sls_tree = steel_sls_config.settings_ec3
    print("\nSTEEL_SETTINGS_EC3_SLS_TREE:")
    print_tree_table(settings_ec3_sls_tree.rows)

    # Get specific value from the tree by its path. The key "l_" is used by
    # every deflection limit of the table, so here the path is what picks out
    # one single value.
    beam_rel_deflection_limit_path=[
        "serviceability_limits",
        "sl_check_limit_characteristic",
        "sl_check_deformation_z_or_resulting_axis_characteristic",
        "l_", # Beam | Relative limit
    ]
    beam_rel_deflection_limit_val = common.get_value_by_path(
        tree=settings_ec3_sls_tree,
        path=beam_rel_deflection_limit_path
    )
    print(f"\nBeam | Relative deflection limit: L/{beam_rel_deflection_limit_val}")

    # Modify the value by path
    common.tree_table.set_value_by_path(
        tree=settings_ec3_sls_tree,
        path=beam_rel_deflection_limit_path,
        value=250
    )

    # Apply the updated configuration to the model
    rfem_app.update_object(
        obj=rfem.steel_design_objects.SteelDesignSlsConfiguration(
            no=1,
            settings_ec3=settings_ec3_sls_tree
        )
    )