Steel Hall#

This example demonstrates how to model a parametric steel hall using manipulation functions like move or rotate including the copy feature.

Create parametric steel portal frame
Enhance rafters with tapering
Replicate frames using vector displacement
Define purlins between frames using symmetry
Model and mirror bracing

from dlubal.api import rfem, common
import math

# -------------------------------------------------------
# This example demonstrates how to modelling parametric
# steel hall with help of manipulation functions like move
# or rotate including the copy option. The idea is to reduce
# manual modeling by leveraging symmetry and transformations.
# -------------------------------------------------------

# Editable parameters (SI units)
FRAME_SPACING = 5.0
FRAME_COUNT = 5
FRAME_WIDTH = 11.0
FRAME_HEIGHT_MIN = 4.5
FRAME_HEIGHT_MAX = 6.0
RAFTER_SLOPE_LENGTH = 0.75
PURLIN_FIELDS = 4
PURLIN_OFFSET_ON_TOP = 0.25

STEEL_GRADE = "S235 | EN 10025-2:2004-11"
CROSS_SECTION_COLUMN = "IPE 300"
CROSS_SECTION_RAFTER = "I 0.3/0.11/0.006/0.014/0/0/H"
CROSS_SECTION_RAFTER_TAPPERED = "I 0.6/0.11/0.006/0.014/0/0/H"
CROSS_SECTION_PURLINS = "CHC 139.7x8.0"
CROSS_SECTION_BRACING = "R 20"


def build_half_portal_frame() -> list:

    inf = float('inf')

    portal_frame = [
        rfem.structure_core.Material(no=1, name=STEEL_GRADE),
        rfem.structure_core.CrossSection(no=1, name=CROSS_SECTION_COLUMN, material=1),
        rfem.structure_core.CrossSection(no=2, name=CROSS_SECTION_RAFTER, material=1),
        rfem.structure_core.CrossSection(no=3, name=CROSS_SECTION_RAFTER_TAPPERED, material=1),
    ]

    portal_frame.append(rfem.structure_core.Node(no=1))
    portal_frame.append(rfem.structure_core.Node(no=2, coordinate_3=-FRAME_HEIGHT_MIN))

    node_no = 3
    rafter_length = math.sqrt((FRAME_HEIGHT_MAX - FRAME_HEIGHT_MIN)**2 + (FRAME_WIDTH / 2)**2)
    purlin_offset = (rafter_length - PURLIN_OFFSET_ON_TOP) / PURLIN_FIELDS

    for j in range(1, PURLIN_FIELDS+1):
        portal_frame.append(
            rfem.structure_core.Node(
                no=node_no,
                type=rfem.structure_core.Node.TYPE_ON_MEMBER,
                on_member_reference_member=2,
                distance_from_start_is_defined_as_relative=False,
                distance_from_start_absolute=purlin_offset*j,
            )
        )
        node_no += 1

    portal_frame.append(rfem.structure_core.Node(no=node_no, coordinate_1=FRAME_WIDTH/2, coordinate_3=-FRAME_HEIGHT_MAX))

    # Lines
    portal_frame.append(rfem.structure_core.Line(no=1, definition_nodes=[1, 2]))
    portal_frame.append(rfem.structure_core.Line(no=2, definition_nodes=[2, node_no]))

    # Members
    portal_frame.append(rfem.structure_core.Member(
        no=1, line=1, cross_section_start=1,
        type=rfem.structure_core.Member.TYPE_BEAM))
    portal_frame.append(rfem.structure_core.Member(
        no=2, line=2, cross_section_start=3,
        type=rfem.structure_core.Member.TYPE_BEAM,
    ))

    # Nodal support (hinge)
    portal_frame.append(rfem.types_for_nodes.NodalSupport(
        no=1, nodes=[1],
        spring_x=inf, spring_y=inf, spring_z=inf,
        rotational_restraint_z=inf
    ))

    return portal_frame


def enhance_rafters_with_tapering() -> list:

    tapered_members = []

    for rafter_no in (2, 4):

        tapered_members.append(
            rfem.structure_core.Member(
                no=rafter_no,
                cross_section_end=2,
                cross_section_distribution_type=rfem.structure_core.Member.CROSS_SECTION_DISTRIBUTION_TYPE_TAPERED_AT_START_OF_MEMBER,
                cross_section_distance_from_start_is_defined_as_relative=False,
                section_distance_from_start_absolute=RAFTER_SLOPE_LENGTH
            )
        )

    return tapered_members


def build_purlins_in_first_bay_half() -> list:

    nodes_per_frame = 7 + 2* (PURLIN_FIELDS)

    purlins = [
        rfem.structure_core.CrossSection(no=4, name=CROSS_SECTION_PURLINS, material=1),
    ]

    for purlin in range(1, PURLIN_FIELDS+2):

        purlin_line_no = (4 * FRAME_COUNT) + purlin
        purlin_node_start = 2 + (purlin - 1)
        purlin_node_end = 2 + (purlin - 1) + nodes_per_frame

        purlins.append(rfem.structure_core.Line(
            no=purlin_line_no, definition_nodes=[purlin_node_start, purlin_node_end])
        )
        purlins.append(rfem.structure_core.Member(
            no=purlin_line_no, line=purlin_line_no, cross_section_start=4,
            type=rfem.structure_core.Member.TYPE_TRUSS)
        )

    return purlins


def build_bracing_in_first_bay_half() -> list:

    nodes_per_frame = 7 + 2* (PURLIN_FIELDS)
    bracing_no = (4 * FRAME_COUNT) + 2*(PURLIN_FIELDS+1)*(FRAME_COUNT-1) + 1

    bracing = [
        rfem.structure_core.CrossSection(no=5, name=CROSS_SECTION_BRACING, material=1)
    ]

    for i in range(1, PURLIN_FIELDS + 2):
        for j in range(2):
            bracing.append(rfem.structure_core.Line(
                no=bracing_no + j, definition_nodes=[i + j, nodes_per_frame + i - j + 1]
            ))
            bracing.append(rfem.structure_core.Member(
                no=bracing_no + j, line=bracing_no + j, cross_section_start=5,
                type=rfem.structure_core.Member.TYPE_TRUSS_ONLY_N
            ))
        bracing_no += 2

    return bracing


def get_members_by_type(rfem_app, member_type) -> list:

    member_list = rfem_app.get_object_list(
        objs=[
            rfem.structure_core.Member()
        ]
    )

    member_list_filtered = []

    for member in member_list:
        if member.type is member_type:
            member_list_filtered.append(member)

    return member_list_filtered


# --- MAIN SCRIPT ---

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

    rfem_app.close_all_models(save_changes=False)
    model_id = rfem_app.create_model(name='steel_hall_parametric')
    rfem_app.delete_all_objects()

    # Build the half of the portal frame
    portal_frame = build_half_portal_frame()
    rfem_app.create_object_list(
        objs=portal_frame
    )

    # Rotate the half of the portal frame as copy to its mirrored position
    rfem_app.rotate_objects(
        objs=portal_frame,
        rotation_angle=math.pi,
        point_1=common.Vector3d(x=FRAME_WIDTH/2,y=0,z=-FRAME_HEIGHT_MAX),
        axis=rfem.manipulation.COORDINATE_AXIS_Z,
        rotation_axis=rfem.manipulation.ROTATION_AXIS_SPECIFICATION_TYPE_POINT_AND_PARALLEL_AXIS,
        create_copy=True,
        number_of_steps=1
    )

    # Enhance the rafters with tapering
    tapered_rafter = enhance_rafters_with_tapering()
    rfem_app.update_object_list(
        objs=tapered_rafter
    )

    # Move the frame to create multiple frames by applying a vector displacement
    rfem_app.move_objects(
        objs=rfem_app.get_object_list(
            objs=[
                rfem.structure_core.Node(),
                rfem.structure_core.Member(),
            ]
        ),
        create_copy=True,
        number_of_steps=FRAME_COUNT-1,
        direction_through=rfem.manipulation.DIRECTION_THROUGH_DISPLACEMENT_VECTOR,
        displacement_vector=common.Vector3d(x=0.0, y=FRAME_SPACING, z=0.0)
    )

    # Model purlins between the first two frames, on one symmetric half of the hall
    purlins = build_purlins_in_first_bay_half()
    rfem_app.create_object_list(objs=purlins)

    # Rotate purlins to symmetric half of the hall
    rfem_app.rotate_objects(
        objs=purlins,
        rotation_angle=math.pi - 2*math.atan((FRAME_HEIGHT_MAX - FRAME_HEIGHT_MIN) / (FRAME_WIDTH / 2)),
        point_1=common.Vector3d(x=FRAME_WIDTH/2,y=0,z=-FRAME_HEIGHT_MAX),
        axis=rfem.manipulation.COORDINATE_AXIS_Y,
        rotation_axis=rfem.manipulation.ROTATION_AXIS_SPECIFICATION_TYPE_POINT_AND_PARALLEL_AXIS,
        create_copy=True,
        number_of_steps=1
    )

    # Copy the purlins parallel to the axis for the remaining bays
    rfem_app.move_objects(
        objs=get_members_by_type(
            rfem_app, rfem.structure_core.Member.TYPE_TRUSS
        ),
        create_copy=True,
        number_of_steps=FRAME_COUNT-2,
        direction_through=rfem.manipulation.DIRECTION_THROUGH_PARALLEL_TO_AXIS,
        axis=rfem.manipulation.COORDINATE_AXIS_Y,
        spacing=FRAME_SPACING
    )

    # Model bracing between the first two frames, on one symmetric half of the hall
    bracing = build_bracing_in_first_bay_half()
    rfem_app.create_object_list(objs=bracing)

    # Mirror the bracing to symetric half of the hall
    rfem_app.rotate_objects(
        objs=get_members_by_type(
            rfem_app, rfem.structure_core.Member.TYPE_TRUSS_ONLY_N
        ),
        rotation_angle=math.pi,
        point_1=common.Vector3d(x=FRAME_WIDTH/2,y=FRAME_SPACING/2,z=-FRAME_HEIGHT_MAX),
        axis=rfem.manipulation.COORDINATE_AXIS_Z,
        rotation_axis=rfem.manipulation.ROTATION_AXIS_SPECIFICATION_TYPE_POINT_AND_PARALLEL_AXIS,
        create_copy=True,
        number_of_steps=1
    )

/**
Parametric steel hall example using manipulation functions.
**/

using Rfem = Dlubal.Api.Rfem;
using Common = Dlubal.Api.Common;
using Google.Protobuf;
using System.Threading.Tasks;

// Editable parameters (SI units)
const double FRAME_SPACING = 5.0;
const int FRAME_COUNT = 5;
const double FRAME_WIDTH = 11.0;
const double FRAME_HEIGHT_MIN = 4.5;
const double FRAME_HEIGHT_MAX = 6.0;
const double RAFTER_SLOPE_LENGTH = 0.75;
const int PURLIN_FIELDS = 4;
const double PURLIN_OFFSET_ON_TOP = 0.25;

const string STEEL_GRADE = "S235 | EN 10025-2:2004-11";
const string CROSS_SECTION_COLUMN = "IPE 300";
const string CROSS_SECTION_RAFTER = "I 0.3/0.11/0.006/0.014/0/0/H";
const string CROSS_SECTION_RAFTER_TAPPERED = "I 0.6/0.11/0.006/0.014/0/0/H";
const string CROSS_SECTION_PURLIN = "CHC 139.7x8.0";
const string CROSS_SECTION_BRACING = "R 20";


static List<IMessage> BuildHalfPortalFrame()
{
    double inf = double.PositiveInfinity;

    var portalFrame = new List<IMessage>
    {
        // Material
        new Rfem.StructureCore.Material{No=1, Name=STEEL_GRADE},

        // Cross-section
        new Rfem.StructureCore.CrossSection{No=1, Name=CROSS_SECTION_COLUMN, Material=1},
        new Rfem.StructureCore.CrossSection{No=2, Name=CROSS_SECTION_RAFTER, Material=1},
        new Rfem.StructureCore.CrossSection{No=3, Name=CROSS_SECTION_RAFTER_TAPPERED, Material=1},
    };

    // Nodes
    portalFrame.Add(new Rfem.StructureCore.Node{No=1});
    portalFrame.Add(new Rfem.StructureCore.Node{No=2, Coordinate3=-FRAME_HEIGHT_MIN});

    var nodeNo = 3;
    var rafterLength = Math.Sqrt(Math.Pow(FRAME_HEIGHT_MAX - FRAME_HEIGHT_MIN, 2) + Math.Pow(FRAME_WIDTH / 2, 2));
    var purlinOffset = (rafterLength - PURLIN_OFFSET_ON_TOP) / PURLIN_FIELDS;

    for (int j = 1; j <= PURLIN_FIELDS; j++)
    {
        var node = new Rfem.StructureCore.Node
        {
            No = nodeNo,
            Type = Rfem.StructureCore.Node.Types.Type.OnMember,
            OnMemberReferenceMember = 2,
            DistanceFromStartIsDefinedAsRelative = false,
            DistanceFromStartAbsolute = purlinOffset * j
        };

        portalFrame.Add(node);
        nodeNo++;
    }

    portalFrame.Add(new Rfem.StructureCore.Node{No=nodeNo, Coordinate1=FRAME_WIDTH/2, Coordinate3=-FRAME_HEIGHT_MAX});

    // Lines
    portalFrame.Add(new Rfem.StructureCore.Line{No=1, DefinitionNodes={1, 2}});
    portalFrame.Add(new Rfem.StructureCore.Line{No=2, DefinitionNodes={2, nodeNo}});

    // Members
    portalFrame.Add(new Rfem.StructureCore.Member{
        No=1, Line=1, CrossSectionStart=1,
        Type=Rfem.StructureCore.Member.Types.Type.Beam
    });
    portalFrame.Add(new Rfem.StructureCore.Member{
        No=2, Line=2, CrossSectionStart=3,
        Type=Rfem.StructureCore.Member.Types.Type.Beam
    });

    // Nodal support (hinge)
    portalFrame.Add(new Rfem.TypesForNodes.NodalSupport{
        No=1, Nodes={ 1 },
        SpringX=inf, SpringY=inf, SpringZ=inf,
        RotationalRestraintZ=inf
    });


    return portalFrame;
}

static List<IMessage> EnhanceRaftersWithTapering()
{
    var taperedMembers = new List<IMessage>();

    foreach (int rafterNo in new int[] { 2, 4 })
    {
        var member = new Rfem.StructureCore.Member
        {
            No = rafterNo,
            CrossSectionEnd = 2,
            CrossSectionDistributionType = Rfem.StructureCore.Member.Types.CrossSectionDistributionType.TaperedAtStartOfMember,
            CrossSectionDistanceFromStartIsDefinedAsRelative = false,
            SectionDistanceFromStartAbsolute = RAFTER_SLOPE_LENGTH
        };

        taperedMembers.Add(member);
    }

    return taperedMembers;
}



static List<IMessage> BuildPurlinsInFirstBayHalf()
{
    int nodesPerFrame = 7 + 2 * PURLIN_FIELDS;

    var purlins = new List<IMessage>
    {
        new Rfem.StructureCore.CrossSection
        {
            No = 4,
            Name = CROSS_SECTION_PURLIN,
            Material = 1
        }
    };

    for (int purlin = 1; purlin <= PURLIN_FIELDS + 1; purlin++)
    {
        int purlinLineNo = (4 * FRAME_COUNT) + purlin;
        int purlinNodeStart = 2 + (purlin - 1);
        int purlinNodeEnd = purlinNodeStart + nodesPerFrame;

        purlins.Add(new Rfem.StructureCore.Line
        {
            No = purlinLineNo,
            DefinitionNodes =
            {
                purlinNodeStart,
                purlinNodeEnd
            }
        });

        purlins.Add(new Rfem.StructureCore.Member
        {
            No = purlinLineNo,
            Line = purlinLineNo,
            CrossSectionStart = 4,
            Type = Rfem.StructureCore.Member.Types.Type.Truss
        });
    }

    return purlins;
}

static List<IMessage> BuildBracingInFirstBayHalf()
{
    int nodesPerFrame = 7 + 2 * PURLIN_FIELDS;

    int bracingNo =
        (4 * FRAME_COUNT)
        + 2 * (PURLIN_FIELDS + 1) * (FRAME_COUNT - 1)
        + 1;

    var bracing = new List<IMessage>
    {
        new Rfem.StructureCore.CrossSection
        {
            No = 5,
            Name = CROSS_SECTION_BRACING,
            Material = 1
        }
    };

    for (int i = 1; i <= PURLIN_FIELDS + 1; i++)
    {
        for (int j = 0; j < 2; j++)
        {
            int currentNo = bracingNo + j;

            bracing.Add(new Rfem.StructureCore.Line
            {
                No = currentNo,
                DefinitionNodes =
                {
                    i + j,
                    nodesPerFrame + i - j + 1
                }
            });

            bracing.Add(new Rfem.StructureCore.Member
            {
                No = currentNo,
                Line = currentNo,
                CrossSectionStart = 5,
                Type = Rfem.StructureCore.Member.Types.Type.TrussOnlyN
            });
        }

        bracingNo += 2;
    }

    return bracing;
}


static async Task<List<IMessage>> GetMembersByType(
    ApplicationRfem rfemApp,
    Rfem.StructureCore.Member.Types.Type memberType)
{
    var result = new List<IMessage>();

    var objects = await rfemApp.get_object_list(
        objs: new List<IMessage>{
            new Rfem.StructureCore.Member{}
        }
    );

    foreach (var obj in objects)
    {
        if (obj is Rfem.StructureCore.Member member &&
            member.Type == memberType)
        {
            result.Add(member);
        }
    }

    return result;
}


ApplicationRfem? rfemApp = null;

try
{
    rfemApp = new ApplicationRfem();

    await rfemApp.close_all_models(saveChanges: false);
    await rfemApp.create_model("steel_hall_parametric");
    await rfemApp.delete_all_objects();

    // Build the half of the portal frame
    var portalFrame = BuildHalfPortalFrame();
    await rfemApp.create_object_list(objs: portalFrame);

    // Rotate the half of the portal frame as copy to its mirrored position
    await rfemApp.rotate_objects(
        objs: portalFrame,
        rotationAngle: Math.PI,
        point1: new Common.Vector3d{X=FRAME_WIDTH/2,Y=0,Z=-FRAME_HEIGHT_MAX},
        axis: Rfem.Manipulation.CoordinateAxis.Z,
        rotationAxis: Rfem.Manipulation.RotationAxisSpecificationType.PointAndParallelAxis,
        createCopy: true,
        numberOfSteps: 1
    );

    // Enhance the rafters with tapering
    var taperedRafterObjs = EnhanceRaftersWithTapering();
    await rfemApp.update_object_list(
        objs: taperedRafterObjs
    );

    // Copy the frame by vector
    await rfemApp.move_objects(
        objs: await rfemApp.get_object_list(
            objs: new List<IMessage> {
                new Rfem.StructureCore.Node {},
                new Rfem.StructureCore.Member {}
            }
        ),
        createCopy: true,
        numberOfSteps: FRAME_COUNT - 1,
        directionThrough: Rfem.Manipulation.DirectionThrough.DisplacementVector,
        displacementVector: new Common.Vector3d{X=0.0, Y=FRAME_SPACING, Z=0.0},
        spacing:FRAME_SPACING
    );

    // Model purlins between the first two frames, on one symmetric half of the hall
    var purlins = BuildPurlinsInFirstBayHalf();
    await rfemApp.create_object_list(objs: purlins);

    // Rotate purlins to symmetric half of the hall
    await rfemApp.rotate_objects(
        objs: purlins,
        rotationAngle: Math.PI - 2*Math.Atan((FRAME_HEIGHT_MAX - FRAME_HEIGHT_MIN) / (FRAME_WIDTH / 2)),
        point1: new Common.Vector3d{X=FRAME_WIDTH/2,Y=0,Z=-FRAME_HEIGHT_MAX},
        axis: Rfem.Manipulation.CoordinateAxis.Y,
        rotationAxis: Rfem.Manipulation.RotationAxisSpecificationType.PointAndParallelAxis,
        createCopy: true,
        numberOfSteps: 1
    );

    // Copy the purlins parallel to the axis for the remaining bays
    await rfemApp.move_objects(
        objs: await GetMembersByType(
            rfemApp, Rfem.StructureCore.Member.Types.Type.Truss
        ),
        createCopy: true,
        numberOfSteps: FRAME_COUNT-2,
        directionThrough: Rfem.Manipulation.DirectionThrough.ParallelToAxis,
        axis: Rfem.Manipulation.CoordinateAxis.Y,
        spacing: FRAME_SPACING
    );

    // Model bracing between the first two frames, on one symmetric half of the hall
    var bracing = BuildBracingInFirstBayHalf();
    await rfemApp.create_object_list(objs: bracing);

    // Mirror the bracing to symetric half of the hall
    await rfemApp.rotate_objects(
        objs: await GetMembersByType(
            rfemApp, Rfem.StructureCore.Member.Types.Type.TrussOnlyN
        ),
        rotationAngle: Math.PI,
        point1: new Common.Vector3d{X=FRAME_WIDTH/2,Y=FRAME_SPACING/2,Z=-FRAME_HEIGHT_MAX},
        axis: Rfem.Manipulation.CoordinateAxis.Z,
        rotationAxis: Rfem.Manipulation.RotationAxisSpecificationType.PointAndParallelAxis,
        createCopy: true,
        numberOfSteps: 1
    );

}

catch (Exception ex)
{
    Console.WriteLine($"Error: {ex.Message}");
}
finally
{
    if (rfemApp != null) await rfemApp.close_connection();
}