Steel Hall#

This example demonstrates how to modelling a parametric steel hall using manipulation functions like move or rotate including the copy feature. The idea is to reduce manual modeling by leveraging symmetry and transformations.

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

    portal_frame.append(rstab.structure_core.Node(no=1))
    portal_frame.append(rstab.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(
            rstab.structure_core.Node(
                no=node_no,
                type=rstab.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(rstab.structure_core.Node(no=node_no, coordinate_1=FRAME_WIDTH/2, coordinate_3=-FRAME_HEIGHT_MAX))

    # Members
    portal_frame.append(rstab.structure_core.Member(
        no=1, node_start=1,  node_end=2, cross_section_start=1,
        type=rstab.structure_core.Member.TYPE_BEAM))
    portal_frame.append(rstab.structure_core.Member(
        no=2, node_start=2, node_end=node_no, cross_section_start=3,
        type=rstab.structure_core.Member.TYPE_BEAM,
    ))

    # Nodal support (hinge)
    portal_frame.append(rstab.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(
            rstab.structure_core.Member(
                no=rafter_no,
                cross_section_end=2,
                cross_section_distribution_type=rstab.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 = [
        rstab.structure_core.CrossSection(no=4, name=CROSS_SECTION_PURLINS, material=1),
    ]

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

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

        purlins.append(rstab.structure_core.Member(
            no=purlin_no, cross_section_start=4,
            node_start= purlin_node_start, node_end= purlin_node_end,
            type=rstab.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 = [
        rstab.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(rstab.structure_core.Member(
                no=bracing_no + j, cross_section_start=5,
                node_start= i + j, node_end= nodes_per_frame + i - j + 1,
                type=rstab.structure_core.Member.TYPE_TRUSS_ONLY_N
            ))
        bracing_no += 2

    return bracing


def get_members_by_type(rstab_app, member_type) -> list:

    member_list = rstab_app.get_object_list(
        objs=[
            rstab.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 rstab.Application() as rstab_app:

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

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

    # Rotate the half of the portal frame as copy to its mirrored position
    rstab_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=rstab.manipulation.COORDINATE_AXIS_Z,
        rotation_axis=rstab.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()
    rstab_app.update_object_list(
        objs=tapered_rafter
    )

    # Move the frame to create multiple frames by applying a vector displacement
    rstab_app.move_objects(
        objs=rstab_app.get_object_list(
            objs=[
                rstab.structure_core.Node(),
                rstab.structure_core.Member(),
            ]
        ),
        create_copy=True,
        number_of_steps=FRAME_COUNT-1,
        direction_through=rstab.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()
    rstab_app.create_object_list(objs=purlins)

    # Rotate purlins to symmetric half of the hall
    rstab_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=rstab.manipulation.COORDINATE_AXIS_Y,
        rotation_axis=rstab.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
    rstab_app.move_objects(
        objs=get_members_by_type(
            rstab_app, rstab.structure_core.Member.TYPE_TRUSS
        ),
        create_copy=True,
        number_of_steps=FRAME_COUNT-2,
        direction_through=rstab.manipulation.DIRECTION_THROUGH_PARALLEL_TO_AXIS,
        axis=rstab.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()
    rstab_app.create_object_list(objs=bracing)

    # Mirror the bracing to symetric half of the hall
    rstab_app.rotate_objects(
        objs=get_members_by_type(
            rstab_app, rstab.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=rstab.manipulation.COORDINATE_AXIS_Z,
        rotation_axis=rstab.manipulation.ROTATION_AXIS_SPECIFICATION_TYPE_POINT_AND_PARALLEL_AXIS,
        create_copy=True,
        number_of_steps=1
    )

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

using Rstab = Dlubal.Api.Rstab;
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 Rstab.StructureCore.Material{No=1, Name=STEEL_GRADE},

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

    // Nodes
    portalFrame.Add(new Rstab.StructureCore.Node{No=1});
    portalFrame.Add(new Rstab.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 Rstab.StructureCore.Node
        {
            No = nodeNo,
            Type = Rstab.StructureCore.Node.Types.Type.OnMember,
            OnMemberReferenceMember = 2,
            DistanceFromStartIsDefinedAsRelative = false,
            DistanceFromStartAbsolute = purlinOffset * j
        };

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

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

    // Members
    portalFrame.Add(new Rstab.StructureCore.Member{
        No=1, NodeStart=1, NodeEnd=2, CrossSectionStart=1,
        Type=Rstab.StructureCore.Member.Types.Type.Beam
    });
    portalFrame.Add(new Rstab.StructureCore.Member{
        No=2, NodeStart=2, NodeEnd=nodeNo, CrossSectionStart=3,
        Type=Rstab.StructureCore.Member.Types.Type.Beam
    });

    // Nodal support (hinge)
    portalFrame.Add(new Rstab.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 Rstab.StructureCore.Member
        {
            No = rafterNo,
            CrossSectionEnd = 2,
            CrossSectionDistributionType = Rstab.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 Rstab.StructureCore.CrossSection
        {
            No = 4,
            Name = CROSS_SECTION_PURLIN,
            Material = 1
        }
    };

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

        purlins.Add(new Rstab.StructureCore.Member
        {
            No = purlinNo,
            NodeStart = purlinNodeStart,
            NodeEnd = purlinNodeEnd,
            CrossSectionStart = 4,
            Type = Rstab.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 Rstab.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 Rstab.StructureCore.Member
            {
                No = currentNo,
                NodeStart = i + j,
                NodeEnd = nodesPerFrame + i - j + 1,
                CrossSectionStart = 5,
                Type = Rstab.StructureCore.Member.Types.Type.TrussOnlyN
            });
        }

        bracingNo += 2;
    }

    return bracing;
}


static async Task<List<IMessage>> GetMembersByType(
    ApplicationRstab rstabApp,
    Rstab.StructureCore.Member.Types.Type memberType)
{
    var result = new List<IMessage>();

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

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

    return result;
}


ApplicationRstab? rstabApp = null;

try
{
    rstabApp = new ApplicationRstab();

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

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

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

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

    // Copy the frame by vector
    await rstabApp.move_objects(
        objs: await rstabApp.get_object_list(
            objs: new List<IMessage> {
                new Rstab.StructureCore.Node {},
                new Rstab.StructureCore.Member {}
            }
        ),
        createCopy: true,
        numberOfSteps: FRAME_COUNT - 1,
        directionThrough: Rstab.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 rstabApp.create_object_list(objs: purlins);

    // Rotate purlins to symmetric half of the hall
    await rstabApp.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: Rstab.Manipulation.CoordinateAxis.Y,
        rotationAxis: Rstab.Manipulation.RotationAxisSpecificationType.PointAndParallelAxis,
        createCopy: true,
        numberOfSteps: 1
    );

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

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

    // Mirror the bracing to symetric half of the hall
    await rstabApp.rotate_objects(
        objs: await GetMembersByType(
            rstabApp, Rstab.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: Rstab.Manipulation.CoordinateAxis.Z,
        rotationAxis: Rstab.Manipulation.RotationAxisSpecificationType.PointAndParallelAxis,
        createCopy: true,
        numberOfSteps: 1
    );

}

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