Defined in File Ifc4x2.h
IfcColumn: public Ifc4x2::IfcBuildingElement¶
Definition from ISO 6707-1:1989: Structural member of slender form, usually vertical, that transmits to its base the forces, primarily in compression, that are applied to it. <An IfcColumn is a vertical structural member which often is aligned with a structural grid intersection. It represents a vertical, or nearly vertical, structural member that transmits, through compression, the weight of the structure above to other structural elements below. It represents such a member from an architectural point of view. It is not required to be load bearing. NOTE The representation of a column in a structural analysis model is provided by IfcStructuralCurveMember being part of an IfcStructuralAnalysisModel.
NOTE For any longitudial structural member, not constrained to be predominately horizontal nor vertical, or where this semantic information is irrelevant, the entity IfcMember exists. The IFC specification provides two entities for column occurrences:
IfcColumnStandardCase used for all occurrences of columns, tthat have a profile defined that is swept along a directrix. The profile might be changed uniformly by a taper definition along the directrix. The profile parameter and its cardinal point of insertion can be fully described by the IfcMaterialProfileSetUsage. These beams are always represented geometricly by an ‘Axis’ and a ‘SweptSolid’ or ‘AdvancedSweptSolid’ shape representation (or by a ‘Clipping’ geometry based on the swept solid), if a 3D geometric representation is assigned. In addition they have to have a corresponding IfcMaterialProfileSetUsage assigned. NOTE View definitions and implementer agreements may further constrain the applicable geometry types, e.g. by excluding tapering from an IfcColumnStandardCase implementation.
IfcColumn used for all other occurrences of columns, particularly for columns with changing profile sizes along the extrusion, or columns defined by non-linear extrusion, or columns having only ‘Brep’, or ‘SurfaceModel’ geometry.
HISTORY New entity in IFC Release 1.0
Type Use Definition IfcColumn defines the occuurence of any column, common information about column types (or styles) is handled by IfcColumnType. The IfcColumnType (if present) may establish the commontype name, usage (or predefined) type, common material layer set, common set of properties and common shape representations (using IfcRepresentationMap). The IfcColumnType is attached using the IfcRelDefinedByType.RelatingType objectified relationship and is accessible by the inverse IsTypedBy attribute. If no IfcColumnType is attached(i.e. if only occurrence information is given) the PredefinedType should be provided. If set to .USERDEFINED. a user defined value can be provided by the ObjectType attribute. Material Use Definition The material of the IfcColumn is defined by the IfcMaterialProfileSet or as fallback by IfcMaterial and attached by the IfcRelAssociatesMaterial.RelatingMaterial. It is accessible by the inverse HasAssociations relationship. Note: It is illegal to assign an IfcMaterialProfileSetUsage to an IfcColumn. Only the subtype IfcColumnStandardCase supports this concept. Material information can also be given at the IfcColumnType, defining the common attribute data for all occurrences of the same type.It is then accessible by the inverse IsTypedBy relationship pointing to IfcColumnType.HasAssociations and via IfcRelAssociatesMaterial.RelatingMaterial to IfcMaterialProfileSet or IfcMaterial. If both are given, then the material directly assigned to IfcColumn overrides the material assigned to IfcColumnType. Property Set Use Definition: The property sets relating to the IfcColumn are defined by the IfcPropertySet and attached by the IfcRelDefinesByProperties relationship. It is accessible by the inverse IsDefinedBy relationship. The following property set definitions specific to the IfcColumn are part of this IFC release:
Pset_ColumnCommon: common property set for all column occurrences
Property sets can also be given at the IfcColumnType, defining the common property data for all occurrences of the same type.It is then accessible by the inverse IsTypedBy relationship pointing to IfcColumnType.HasPropertySets. If both are given, then the properties directly assigned to IfcColumn overrides the properties assigned to IfcColumnType. Quantity Use Definition: The quantities relating to the IfcColumn are defined by the IfcElementQuantity and attached by the IfcRelDefinesByProperties. It is accessible by the inverse IsDefinedBy relationship. The following base quantities are defined and should be exchanged with the IfcElementQuantity.MethodOfMeasurement = ‘BaseQuantities’. Other quantities can be defined being subjected to local standard of measurement with another string value assigned to Name and a value provided for MethodOfMeasurement. Quanties shall be never assigned to the IfcColumnType.
Qto_ColumnBaseQuantities: base quantities for all column occurrences.
Containment Use Definition The IfcColumn, as any subtype of IfcBuildingElement, may participate in two different containment relationships. The first (and in most implementation scenarios mandatory) relationship is the hierachical spatial containment, the second (optional) relationship is the aggregation within anelement assembly.
The IfcColumn, is places within the project spatial hierarchy using the objectified relationship IfcRelContainedInSpatialStructure, refering to it by its inverse attribute SELF\IfcElement.ContainedInStructure. Subtypes ofIfcSpatialStructureElement are valid spatial containers, with IfcBuildingStorey being the default container. The IfcColumn, may be aggregated into an element assembly using the objectified relationship IfcRelAggregates, refering to it by its inverse attribute SELF\IfcObjectDefinition.Decomposes. Any subtype of IfcElement can be an element assembly, with IfcElementAssembly as a special focus subtype. In this case it should not be additionally contained in the project spatial hierarchy, i.e.SELF\IfcElement.ContainedInStructure should be NIL.
Geometry Use Definition The geometric representation of IfcColumn is given by the IfcProductDefinitionShape, allowing multiple geometric representations. Included are: Local Placement The local placement for IfcColumn is defined in its supertype IfcProduct. It is defined by the IfcLocalPlacement, which defines the local coordinate system that is referenced by all geometric representations.
The PlacementRelTo relationship of IfcLocalPlacement shall point (if given) to the local placement of the same IfcSpatialStructureElement, which is used in the ContainedInStructure inverse attribute, or to a spatial structure element at a higher level, referenced by that. If the relative placement is not used, the absolute placement is defined within the world coordinate system.
Geometric Representation Currently, the ‘Axis’, ‘Body’, and ‘Box’ representations are supported. The ‘Box’ representation includes the representation type ‘BoundingBox’ and is explained at IfcBuildingElement. Axis Representation The axis geometric representation of IfcColumn is defined using the ‘Axis’ representation. The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:
RepresentationIdentifier : ‘Axis’ RepresentationType : ‘Curve2D’, ‘Curve3D’
The axis representation can be used to represent the system length of a column that may extent the body length of the column. Body Representation The body representation of IfcColumn can be represented using the representation types ‘SweptSolid’, ‘Clipping’, ‘AdvancedSweptSolid’, ‘MappedRepresentation’, ‘SurfaceModel’, and ‘Brep’. The representation types ‘SurfaceModel’ and ‘Brep’ are explained at IfcBuildingElement. 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 Profile: all subtypes of IfcProfileDef (with exception of IfcArbitraryOpenProfileDef) Extrusion:All extrusion directions shall be supported
Figure 81 illustrates a ‘SweptSolid’ geometric representation. There are no restrictions or conventions on how to use the local placement (black), solid of extrusion placement (red) and profile placement (green).
Figure 81 — Column swept solid
Figure 82 — Column extrusion of I-Shape
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 advanced representation:
Solid: see ‘SweptSolid’ geometric representation Profile: see ‘SweptSolid’ geometric representation Extrusion: 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.
Figure 83 — Column clipping
AdvancedSweptSolid Representation Type 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 agreements can further constrain the allowed swept solid types.
Profile: see ‘SweptSolid’ geometric representation Extrusion:not applicable
MappedRepresentation Representation Type The ‘MappedRepresentation’ representation type is supported as it allows for reusing the geometry definition of the beam type at all occurrences of the same type. The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:
RepresentationIdentifier : ‘Body’ RepresentationType : ‘MappedRepresentation’
The same constraints, as given for the ‘SweptSolid’, ‘Clipping’, ‘AdvancedSweptSolid’, ‘SurfaceModel’ and ‘Bre’ geometric representation, shall apply to the MappedRepresentation of the IfcRepresentationMap.
Subclassed by Ifc4x2::IfcColumnStandardCase
Whether the optional attribute PredefinedType is defined for this IfcColumn.
Predefined generic type for a column that is specified in an enumeration. There may be a property set given specificly for the predefined types. NOTE The PredefinedType shall only be used, if no type object IfcColumnType is assigned, providing its own IfcColumnType.PredefinedType.
IFC2x4 CHANGE The attribute has been added at the end of the entity definition.
IfcColumn(std::string v1_GlobalId, ::Ifc4x2::IfcOwnerHistory *v2_OwnerHistory, boost::optional<std::string> v3_Name, boost::optional<std::string> v4_Description, boost::optional<std::string> v5_ObjectType, ::Ifc4x2::IfcObjectPlacement *v6_ObjectPlacement, ::Ifc4x2::IfcProductRepresentation *v7_Representation, boost::optional<std::string> v8_Tag, boost::optional<::Ifc4x2::IfcColumnTypeEnum::Value> v9_PredefinedType)¶