Class Ifc4::IfcBeamStandardCase

Nested Relationships

This class is a nested type of Struct Ifc4.

Inheritance Relationships

Base Type

Class Documentation

class Ifc4::IfcBeamStandardCase : public Ifc4::IfcBeam

The standard beam, IfcBeamStandardCase, defines a beam with certain constraints for the provision of material usage, parameters and with certain constraints for the geometric representation. The IfcBeamStandardCase handles all cases of beams, that:

have a reference to the IfcMaterialProfileSetUsage defining the material profile association of the beam with the cardinal point of its insertion relative to the local placement. are consistent in using the correct cardinal point offset of the profile as compared to the ‘Axis’ and ‘Body’ shape representation are based on a sweep of a planar profile, or set of profiles, as defined by the IfcMaterialProfileSet have an ‘Axis’ shape representation with constraints provided below in the geometry use definition have a ‘Body’ shape representation with constraints provided below in the geometry use definition

are extruded perpendicular to the profile definition plane have a start profile, or set of profiles, that is swept the sweeping operation can be linear extrusion, circular rotation, or a sweep along a directrix the start profile, or set of profiles can be swept unchanged, or might be changed uniformly by a taper definition

NOTE View definitions and implementer agreements may further constrain the applicable geometry types, e.g. by excluding tapering from an IfcBeamStandardCase implementation.

HISTORY New entity in IFC2x4.

Type Use Definition IfcBeam defines the occurrence of any beam, common information about beam types (or styles) is handled by IfcBeamType. The IfcBeamType (if present) may establish the common type name, usage (or predefined) type, common set of properties, and common material profile set (combining profiles and material of profile). The IfcBeamType is attached using the IfcRelDefinedByType.RelatingType objectified relationship and is accessible by the inverse IsTypedBy attribute. The IfcBeamStandardCase defines in addition that the IfcBeamType should have a unique IfcMaterialProfileSet, that is referenced by the IfcMaterialProfileSetUsage that is assigned to all occurrences of this beam type.

Figure 74 illustrates assignment of IfcMaterialProfileSetUsage and IfcMaterialProfileSet to the IfcBeamStandardCase as the beam occurrence and to the IfcBeamType. The same IfcMaterialProfileSet shall be shared by many occurrences of IfcMaterialProfileSetUsage. This relationship shall be consistent to the relationship between the IfcBeamType and the IfcBeamStandardCase.

Figure 74 — Beam profile usage

Figure 75 illustrates alignment of cardinal points. NOTE It has to be guaranteed that the use of IfcCardinalPointEnum is consistent to the placement of the extrusion body provided by IfcExtrudedAreaSolid.Position NOTE The cardinal points 8 (top centre) and 6 (mid-depth right) are assigned according to the definition at IfcCardinalPointReference

Figure 75 — Beam cardinal points

Figure 76 illustrates assignment of a composite profile by using IfcCompositeProfile for geometric representation and several IfcMaterialProfile’s within the IfcMaterialProfileSet.

Figure 76 — Beam composite profiles

Material Use Definition The material of the IfcBeamStandardCase is defined by IfcMaterialProfileSetUsage and attached by the IfcRelAssociatesMaterial.RelatingMaterial. It is accessible by the inverse HasAssociations relationship. Composite profile beams can be represented by refering to several IfcMaterialProfile’s within the IfcMaterialProfileSet that is referenced from the IfcMaterialProfileSetUsage. See Type Use Definition for additional agreements for material assignement to IfcBeamStandardCase and IfcBeamType. Property Set Use Definition: The property sets relating to the IfcBeamStandardCase are defined at the supertype IfcBeam. Quantity Use Definition The quantities relating to the IfcBeamStandardCase are defined at the supertype IfcBeam. Containment Use Definition The containment use definitions relating to the IfcBeamStandardCase are defined at the supertype IfcBeam. Geometry Use Definitions: The geometric representation of IfcBeamStandardCase is given by the IfcProductDefinitionShape, allowing multiple geometric representations. Included are: Local Placement The general use of local placement is defined at the supertype IfcBeam. The following restriction is imposed:

The local placement shall provide the location and directions for the standard beam, the x/y plane is the plane for the start profile, and the z-axis is the extrusion axis for the beam body (in case of rotation, the tangent direction).

Geometric Representations The geometric representation of IfcBeamStandardCase is defined using the following multiple shape representations for its definition:

Axis: A three dimensional open curve (subtype of IfcBoundedCurve) defining the axis for the standard beam. The cardinal point is determined by the beam axis. Body: A Swept Solid Representation or a CSG clipping representation defining the 3D shape of the standard beam.

NOTE It is invalid to exchange a ‘SurfaceModel’, ‘Brep’, or ‘MappedRepresentation’ representation for the ‘Body’ shape representation of an IfcBeamStandardCase. Axis Representation The axis geometric representation of IfcBeamStandardCase is defined using the ‘Axis’ representation. The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:

RepresentationIdentifier : ‘Axis’ RepresentationType : ‘Curve3D’

The following additional constraints apply to the ‘Axis’ representation, if the ‘Body’ shape representation has the RepresentationType : ‘SweptSolid’:

Axis :

IfcPolyline having two Points, or IfcTrimmedCurve with BasisCurve of Type IfcLine for ‘SweptSolid’ provided as IfcExtrudedAreaSolid. The axis curve lies on the z axis of the object coordinate system. IfcTrimmedCurve with BasisCurve of Type IfcCircle for ‘SweptSolid’ provided as IfcRevolvedAreaSolid. The axis curve lies on the x/z plane of the object coordinate system, the tangent at the start is along the positive z-axis.

As shown in Figure 77, the axis shall be defined along the z axis of the object coordinate system. The axis representation can be used to represent the system length of a beam that may extent the body length of the beam.

Figure 77 — Beam axis representation

As shown in Figure 78, the axis representation shall be used to represent the cardinal point as the offset between the ‘Axis’ and the extrusion path of the beam. The extrusion path is provided as IfcExtrudedAreaSolid.ExtrudedDirection and should be parallel to the ‘Axis’ and the z axis. It has to be guaranteed that the value provided by IfcMaterialProfileSetUsage.CardinalPoint is consistent to the IfcExtrudedAreaSolid.Position.

Figure 78 — Beam axis cardinal point

Body Representation The body representation of IfcBeamStandardCase can be represented using the representation types ‘SweptSolid’, ‘Clipping’, or ‘AdvancedSweptSolid’. SweptSolid Representation Type The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:

RepresentationIdentifier : ‘Body’ RepresentationType : ‘SweptSolid’

The following additional constraints apply to the ‘SweptSolid’ representation:

Solid: IfcExtrudedAreaSolid, IfcRevolvedAreaSolid shall be supported Solid Position : The IfcSweptAreaSolid.Position shall exclusively been used to correspond to the cardinal point. The x/y offset of the Position represents the cardinal point offset of the profile against the axis. No rotation shall be allowed. Profile: All subtypes of IfcParameterizedProfileDef Profile Position : For all single profiles, the IfcParameterizedProfileDef.Position shall be NIL, or having Location = 0.,0. and RefDirection = 1.,0. Extrusion:Perpendicular to the profile direction. The IfcExtrudedAreaSolid.ExtrudedDirection shall be [0.,0.,1.]. Orientation: The y-axis of the profile, as determined by IfcSweptAreaSolid.Position.P[2] shall point upwards. It indicates the “role” of the beam, a role=0° means y-axis of profile pointing upwards.

Figure 79 illustrates a standard geometric representation with cardinal point applied as 1 (bottom left). The following interpretation of dimension parameter applies for rectangular beams with linear extrusions:

IfcRectangleProfileDef.YDim interpreted as beam height IfcRectangleProfileDef.XDim interpreted as beam width

The following interpretation of dimension parameter applies for circular beams:

IfcCircleProfileDef.Radius interpreted as beam radius.

Figure 79 — Beam body extrusion

Clipping Representation Type The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:

RepresentationIdentifier : ‘Body’ RepresentationType : ‘Clipping’

The following constraints apply to the ‘Clipping’ representation:

Solid : see ‘SweptSolid’ geometric representation Solid Position : see ‘SweptSolid’ geometric representation Profile : see ‘SweptSolid’ geometric representation Profile Position : see ‘SweptSolid’ geometric representation Extrusion : see ‘SweptSolid’ geometric representation Orientation : see ‘SweptSolid’ geometric representation Boolean result: The IfcBooleanClippingResult shall be supported, allowing for Boolean differences between the swept solid (here IfcExtrudedAreaSolid) and one or several IfcHalfSpaceSolid (or its subtypes).

Figure 80 illustrates a ‘Clipping’ geometric representation with use of IfcBooleanClippingResult between an IfcExtrudedAreaSolid and an IfcHalfSpaceSolid to create a clipped body, with cardinal point applied as 4 (mid-depth left)

Figure 80 — Beam body clipping

AdvancedSweptSolid Representation Type The ‘AdvancedSweptSolid’ representation type is a valid body representation of IfcBeamStandardCase. The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:

RepresentationIdentifier : ‘Body’ RepresentationType : ‘AdvancedSweptSolid’

The following additional constraints apply to the ‘AdvancedSweptSolid’ representation type:

Solid: IfcSurfaceCurveSweptAreaSolid, IfcFixedReferenceSweptAreaSolid, IfcExtrudedAreaSolidTapered, IfcRevolvedAreaSolidTapered shall be supported. NOTE View definitions and implementer agreement can further constrain the allowed swept solid types.

Solid Position : see ‘SweptSolid’ geometric representation Profile: see ‘SweptSolid’ geometric representation Profile Position : see ‘SweptSolid’ geometric representation Extrusion:not applicable

Public Types

typedef IfcTemplatedEntityList<IfcBeamStandardCase> list

Public Functions

const IfcParse::entity &declaration() const
IfcBeamStandardCase(IfcEntityInstanceData *e)
IfcBeamStandardCase(std::string v1_GlobalId, ::Ifc4::IfcOwnerHistory *v2_OwnerHistory, boost::optional<std::string> v3_Name, boost::optional<std::string> v4_Description, boost::optional<std::string> v5_ObjectType, ::Ifc4::IfcObjectPlacement *v6_ObjectPlacement, ::Ifc4::IfcProductRepresentation *v7_Representation, boost::optional<std::string> v8_Tag, boost::optional<::Ifc4::IfcBeamTypeEnum::Value> v9_PredefinedType)

Public Static Functions

const IfcParse::entity &Class()