Beam to Column Flange

Creating a beam-to-column end-plate steel joint and reading its governing design checks: Create a steel column and beam model with supports and nodal loads Activate the Steel Joints add-on and define ULS and stiffness configurations Add an end plate with bolts, welds, and two column stiffeners Calculate the model and print maximum plate, bolt, and weld design ratios Filter detailed bolt check results and print selected resistance values Keywords: steel joint beam to column end plate bolts stiffeners design ratios

PythonC#

from math import inf

from dlubal.api import rfem, common
from dlubal.api.common.packing import wrap_value
import re

# -------------------------------------------------------
# This example demonstrates how to create a simple steel joint in RFEM.
# It defines a column and beam connection, activates the Steel Joints add-on,
# and creates joint components for an end plate and stiffeners.
# -------------------------------------------------------


# Editable parameters (SI units)

COLUMN_CROSS_SECTION = "HEA 300"
BEAM_CROSS_SECTION = "IPE 400"

STEEL_GRADE = "S355"
BOLT_SIZE = "M16"
BOLT_GRADE = "8.8"
PLATE_THICKNESS = "0.014"
STIFFENER_THICKNESS = "0.014"


def define_structure() -> list:
    """Define the base RFEM model required by the steel joint."""

    return [
        # Materials
        rfem.structure_core.Material(
            no=1,
            name=STEEL_GRADE,
        ),

        # Cross-Sections
        rfem.structure_core.CrossSection(
            no=1,
            material=1,
            name=COLUMN_CROSS_SECTION,
        ),
        rfem.structure_core.CrossSection(
            no=2,
            material=1,
            name=BEAM_CROSS_SECTION,
        ),

        # Nodes
        rfem.structure_core.Node(
            no=1,
            coordinate_1=0.0,
            coordinate_2=0.0,
            coordinate_3=0.0,
        ),
        rfem.structure_core.Node(
            no=2,
            type=rfem.structure_core.Node.TYPE_ON_MEMBER,
            on_member_reference_member=1,
            distance_from_start_is_defined_as_relative=False,
            distance_from_start_absolute=1.0,
        ),
        rfem.structure_core.Node(
            no=3,
            coordinate_1=1.0,
            coordinate_2=0.0,
            coordinate_3=-1.0,
        ),
        rfem.structure_core.Node(
            no=4,
            coordinate_1=0.0,
            coordinate_2=0.0,
            coordinate_3=-2.0,
        ),

        # Lines
        rfem.structure_core.Line(
            no=1,
            definition_nodes=[1, 4],
        ),
        rfem.structure_core.Line(
            no=3,
            definition_nodes=[2, 3],
        ),

        # Members
        rfem.structure_core.Member(
            no=1,
            line=1,
            type=rfem.structure_core.Member.TYPE_BEAM,
            cross_section_start=1,
        ),


        rfem.structure_core.Member(
            no=3,
            line=3,
            type=rfem.structure_core.Member.TYPE_BEAM,
            cross_section_start=2,
        ),

        # Nodal Supports
        rfem.types_for_nodes.NodalSupport(
            no=1,
            nodes=[1],
            spring_x=inf,
            spring_y=inf,
            spring_z=inf,
            rotational_restraint_x=inf,
            rotational_restraint_y=inf,
            rotational_restraint_z=inf,
        ),
    ]


def define_loading() -> list:
    """Define a load case and one nodal force at the free beam end."""

    return [
        rfem.loading.StaticAnalysisSettings(
            no=1,
        ),
        rfem.loading.LoadCase(
            no=1,
            name="Nodal force",
            static_analysis_settings=1,
            self_weight_active=False,
        ),
        rfem.loading.DesignSituation(
            no=1,
            name="ULS (STR/GEO) - Permanent and transient - Eq. 6.10",
            design_situation_type=rfem.loading.DesignSituation.DESIGN_SITUATION_TYPE_STR_PERMANENT_AND_TRANSIENT_6_10,
            active_for_steel_joints=True,
        ),
        rfem.loading.LoadCombination(
            no=1,
            design_situation=1,
            name="CO1 - 1.0 * LC1",
            static_analysis_settings=1,
            items=rfem.loading.LoadCombination.ItemsTable(
                rows=[
                    rfem.loading.LoadCombination.ItemsRow(
                        no=1,
                        factor=1.0,
                        load_case=1,
                    ),
                ]
            ),
            combination_rule_str="1.0*LC1",
        ),
        rfem.loads.NodalLoad(
            no=1,
            nodes=[3],
            load_case=1,
            force_magnitude=70000,
            load_direction=rfem.loads.NodalLoad.LOAD_DIRECTION_GLOBAL_Z_OR_USER_DEFINED_W_TRUE_LENGTH,
        ),
        rfem.loads.NodalLoad(
            no=2,
            nodes=[4],
            load_case=1,
            components_force=common.Vector3d(z=20000),
            components_moment=common.Vector3d(y=25000),
            load_type=rfem.loads.NodalLoad.LOAD_TYPE_COMPONENTS
        ),
    ]


def define_joint_members():
    """Define members assigned inside the Steel Joint add-on table."""

    return rfem.steel_joints_objects.SteelJoint.MembersTable(
        rows=[
            rfem.steel_joints_objects.SteelJoint.MembersRow(
                no=1,
                is_active=True,
                members_no=[1],
                status="Column",
                end_type=rfem.steel_joints_objects.SteelJoint.MembersRow.EndType.END_TYPE_MEMBER_CONTINUOUS,
                supported=True,
            ),
            rfem.steel_joints_objects.SteelJoint.MembersRow(
                no=2,
                is_active=True,
                members_no=[3],
                status="Beam",
                end_type=rfem.steel_joints_objects.SteelJoint.MembersRow.EndType.END_TYPE_MEMBER_ENDED,
                supported=False,
            ),
        ]
    )


def define_joint_components():
    """Define top-level Steel Joint components and their RFEM setting keys."""

    joint_components = [
        (
            rfem.steel_joints_objects.SteelJoint.ComponentsRow.Type.TYPE_END_PLATE,
            "End Plate 1",
            [
                ("connected_member_1", "Beam"),
                ("reference_member", "Column"),
                ("plate_material_1", 1),
                ("plate_shape_1", 0),
                ("plate_thickness_1", PLATE_THICKNESS),
                ("plate_definition_type_1", 0),
                ("plate_top_offset_1", 0.01),
                ("plate_bottom_offset_1", 0.01),
                ("plate_left_offset_1", 0.005),
                ("plate_right_offset_1", 0.005),
                ("bolt_size", "M16"),
                ("bolt_strength_grade", "8.8"),
                ("bolt_horizontal_count", 2),
                ("bolt_horizontal_spacing", "0.0450 0.0900 0.0450"),
                ("bolt_vertical_count", 3),
                ("bolt_vertical_spacing", "0.0600 0.0500 0.1500 0.0600"),
                ("bolt_prestressed_bolts", False),
                ("bolt_shear_plane_in_thread", True),
                ("plate_1_bolt_is_active_1", True),
                ("plate_1_bolt_is_active_2", True),
                ("plate_1_bolt_is_active_3", True),
                ("plate_1_bolt_is_active_4", True),
                ("plate_1_bolt_is_active_5", True),
                ("plate_1_bolt_is_active_6", True),
                ("weld_is_active_1", True),
                ("weld_is_active_2", True),
                ("weld_is_active_3", True),
                ("weld_type_1", 2),
                ("weld_type_2", 2),
                ("weld_type_3", 2),
                ("weld_material_1", "Double fillet weld"),
                ("weld_material_2", "Double fillet weld"),
                ("weld_material_3", "Double fillet weld"),
                ("weld_size_1", 0.003),
                ("weld_size_2", 0.003),
                ("weld_size_3", 0.003),
            ],
        ),
        (
            rfem.steel_joints_objects.SteelJoint.ComponentsRow.Type.TYPE_STIFFENER,
            "Stiffener 1",
            [
                ("stiffened_member", "Column"),
                ("reference_member", "Beam"),
                ("plate_material", 1),
                ("plate_thickness", STIFFENER_THICKNESS),
                ("plate_count", 1),
                ("position", 4),
                ("reference_member_plate", "Flange 1"),
                ("direction", 0),
                ("location_offset", "0.0000"),
                ("side", 2),
                ("inclination", 0.0),
                ("width_offset", 0.0),
                ("height_offset", 0.0),
                ("chamfer", 0.025),
                ("weld_is_active_1", True),
                ("weld_is_active_2", True),
                ("weld_is_active_3", True),
                ("weld_type_1", 2),
                ("weld_type_2", 2),
                ("weld_type_3", 2),
                ("weld_material_1", 1),
                ("weld_material_2", 1),
                ("weld_material_3", 1),
                ("weld_size_1", 0.003),
                ("weld_size_2", 0.003),
                ("weld_size_3", 0.003),
            ],
        ),
        (
            rfem.steel_joints_objects.SteelJoint.ComponentsRow.Type.TYPE_STIFFENER,
            "Stiffener 2",
            [
                ("stiffened_member", "Column"),
                ("reference_member", "Beam"),
                ("plate_material", 1),
                ("plate_thickness", STIFFENER_THICKNESS),
                ("plate_count", 1),
                ("position", 4),
                ("reference_member_plate", "Flange 2"),
                ("direction", 1),
                ("location_offset", "0.0000"),
                ("side", 2),
                ("inclination", 0.0),
                ("width_offset", 0.0),
                ("height_offset", 0.0),
                ("chamfer", 0.0),
                ("weld_is_active_1", True),
                ("weld_is_active_2", True),
                ("weld_is_active_3", True),
                ("weld_type_1", 2),
                ("weld_type_2", 2),
                ("weld_type_3", 2),
                ("weld_material_1", 1),
                ("weld_material_2", 1),
                ("weld_material_3", 1),
                ("weld_size_1", 0.003),
                ("weld_size_2", 0.003),
                ("weld_size_3", 0.003),
            ],
        ),
    ]

    joint_component_rows = []

    for component_no, joint_component in enumerate(joint_components, start=1):
        component_type, component_name, component_settings = joint_component
        setting_rows = []

        for setting_no, setting in enumerate(component_settings, start=1):
            setting_key, setting_value = setting

            setting_rows.append(
                rfem.steel_joints_objects.SteelJoint.ComponentsRow.SettingsTableRow(
                    no=setting_no,
                    key=setting_key,
                    value=wrap_value(setting_value),
                )
            )

        joint_component_rows.append(
            rfem.steel_joints_objects.SteelJoint.ComponentsRow(
                no=component_no,
                is_active=True,
                type=component_type,
                name=component_name,
                settings=rfem.steel_joints_objects.SteelJoint.ComponentsRow.SettingsTable(
                    rows=setting_rows,
                ),
            )
        )

    return rfem.steel_joints_objects.SteelJoint.ComponentsTable(
        rows=joint_component_rows,
    )


def define_steel_joint() -> list:
    """Define the steel joint and its design configurations"""

    return [
        rfem.steel_joints_design_addon_objects.JointUlsConfiguration(
            no=1,
            name="ULS Configuration",
        ),
        rfem.steel_joints_design_addon_objects.JointStiffnessAnalysisConfiguration(
            no=1,
            name="Stiffness Analysis Configuration",
        ),
        rfem.steel_joints_objects.SteelJoint(
            no=1,
            nodes=[2],
            user_defined_name_enabled=True,
            name="Nodes : 2 | Created via API",
            comment="Created via API",
            ultimate_configuration=1,
            stiffness_analysis_configuration=1,
            members=define_joint_members(),
            components=define_joint_components(),
        ),
    ]


def get_max_design_check_row(design_ratios_df, design_check_type: str):
    """Return the design result row with the maximum design ratio for a check type."""

    design_checks = design_ratios_df.loc[
        design_ratios_df["design_check_type"] == design_check_type
    ]
    if design_checks.empty:
        raise ValueError(f"No design check results found for {design_check_type}.")

    return design_checks.loc[design_checks["design_ratio"].idxmax()]


def get_design_check_value_by_key(design_check_details_df, key) -> str:
    """
    This function extracts the 'value', 'unit', and 'caption' from the design check details
    based on the specified 'key'. The unit string is cleaned to remove any HTML tags.
    """
    row = design_check_details_df.loc[design_check_details_df['key'] == key]

    if row.empty:
        raise ValueError(f"Key '{key}' not found in design check details.")

    caption = row['caption'].values[0]
    key = row['key'].values[0]
    value = row['value'].values[0]
    unit = row['unit'].values[0]

    # Remove HTML tags from unit string
    unit_clean = re.sub(r"<[^>]+>", "", str(unit))

    return f"{key} = {value} [{unit_clean}]\t| {caption}"

# -------------------------------------------------------
# MAIN SCRIPT
# -------------------------------------------------------

with rfem.Application() as rfem_app:

    # Initialize model
    rfem_app.close_all_models(save_changes=False)
    rfem_app.create_model(name='end_plate_moment_connection')

    # Edit base data
    base_data = rfem_app.get_base_data()
    base_data.addons.steel_joints_active = True
    rfem_app.set_base_data(base_data=base_data)

    # Create model
    rfem_app.delete_all_objects()
    rfem_app.create_object_list(
        define_structure() +
        define_loading() +
        define_steel_joint()
    )

    # Calculate design
    rfem_app.calculate_all(skip_warnings=True)

    # Retrieve maximum design check ratio summary
    design_ratios_df: common.Table = rfem_app.get_results(
        results_type=rfem.results.ResultsType.STEEL_JOINTS_DESIGN_RATIOS,
    ).data

    max_plate_check = get_max_design_check_row(design_ratios_df, "UL1000.00")   # Plates
    max_bolt_check = get_max_design_check_row(design_ratios_df, "UL1100.00")    # Bolts
    max_weld_check = get_max_design_check_row(design_ratios_df, "UL1200.00")    # Welds

    print("Design check summary:")
    print(f"Plates: {max_plate_check['design_ratio']}")
    print(f"Bolts: {max_bolt_check['design_ratio']}")
    print(f"Welds: {max_weld_check['design_ratio']}")


    # Retrieve details for bolt check of maximum tension resistance
    bolt_check_details_id = int(max_bolt_check["design_check_details_id"])
    bolt_check_details_df = rfem_app.get_results(
        results_type=rfem.results.ResultsType.STEEL_JOINTS_DESIGN_CHECK_DETAILS,
        filters=[
            rfem.results.ResultsFilter(
                column_id="design_check_details_id",
                filter_expression=str(bolt_check_details_id),
            )
        ],
    ).data

    print(f"\nBolt | Tension resistance:")
    print(get_design_check_value_by_key(bolt_check_details_df, key='f_t_ed'))
    print(get_design_check_value_by_key(bolt_check_details_df, key='f_ub'))
    print(get_design_check_value_by_key(bolt_check_details_df, key='k_2'))
    print(get_design_check_value_by_key(bolt_check_details_df, key='f_t_rd'))
    print(get_design_check_value_by_key(bolt_check_details_df, key='eta_ft'))