#### IfcBeam

Natural language names

##### Semantic definitions at the entity

Entity definition

Definition from ISO 6707-1:1989: Structural member designed to carry loads between or beyond points of support, usually narrow in relation to its length and horizontal or nearly so.

An IfcBeam is a horizontal, or nearly horizontal, structural member. It represents such a member from an architectural point of view. It is not required to be load bearing.

> NOTE For any longitudinal structural member, not constrained to be predominately horizontal nor vertical, or where this semantic information is irrelevant, the entity IfcMember exists.

> HISTORY New entity in IFC Release 1.0

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 material layer set, common set of properties and common shape representations (using IfcRepresentationMap). The IfcBeamType is attached using the IfcRelDefinedByType.RelatingType objectified relationship and is accessible by the inverse IsDefinedBy attribute.

If no IfcBeamType is attached (i.e. if only occurrence information is given) the predefined type may be given by using the ObjectType attribute. Recommended values are 'beam' (the default), 'brace', 'joist', 'rafter', 'stringer'.

Property Set Use Definition:

The property sets relating to the IfcBeam 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 IfcBeam are part of this IFC release:

- Pset_BeamCommon: common property set for all beam occurrences

Material Use Definition

The material of the IfcBeam is defined by the IfcMaterial or IfcMaterialList and attached by the IfcRelAssociatesMaterial.RelatingMaterial. It is accessible by the inverse HasAssociations relationship. Material information can also be given at the IfcBeamType, defining the common attribute data for all occurrences of the same type. It is then accessible by the inverse IsDefinedBy relationship pointing toIfcBeamType.HasAssociations and via IfcRelAssociatesMaterial.RelatingMaterial to IfcMaterial or IfcMaterialList. If both are given, then the material directly assigned to IfcBeam overrides the material assigned to IfcBeamType.

Quantity Use Definition:

The quantities relating to the IfcBeam are defined by the IfcElementQuantity and attached by the IfcRelDefinesByProperties relationship. It is accessible by the inverse IsDefinedBy relationship. The following quantities are foreseen, but will be subjected to the local standard of measurement used:

Name | Description | Value Type
NominalLength | Total nominal length of the beam, not taking into account any cut-out's or other processing features. | IfcQuantityLength
CrossSectionArea | Total area of the cross section (or profile) of the beam. The exact definition and calculation rules depend on the method of measurement used. | IfcQuantityArea
OuterSurfaceArea | Total area of the extruded surfaces of the beam (not taking into account the end cap areas), normally generated as perimeter * length. | IfcQuantityArea
TotalSurfaceArea | Total area of the beam, normally generated as perimeter * length + 2 * cross section area. | IfcQuantityArea
GrossVolume | Total gross volume of the beam, not taking into account possible processing features (cut-out's, etc.) or openings and recesses. The exact definition and calculation rules depend on the method of measurement used. | IfcQuantityVolume
NetVolume | Total net volume of the beam, taking into account possible processing features (cut-out's, etc.) or openings and recesses. The exact definition and calculation rules depend on the method of measurement used. | IfcQuantityVolume
GrossWeight | Total gross weight of the beam without add-on parts, not taking into account possible processing features (cut-out's, etc.) or openings and recesses. | IfcQuantityWeight
NetWeight | Total net weight of the beam without add-on parts, taking into account possible processing features (cut-out's, etc.) or openings and recesses. | IfcQuantityWeight

Containment Use Definition

The IfcBeam, 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 an element assembly.

- The IfcBeam is places within the project spatial hierarchy using the objectified relationship IfcRelContainedInSpatialStructure, referring to it by its inverse attribute SELF\IfcElement.ContainedInStructure. Subtypes of IfcSpatialStructureElement are valid spatial containers, with IfcBuildingStorey being the default container.
- The IfcBeam may be aggregated into an element assembly using the objectified relationship IfcRelAggregates, referring 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 Definitions:

The geometric representation of IfcBeam is given by the IfcProductDefinitionShape, allowing multiple geometric representations. Included are:

Local Placement

The local placement for IfcBeam 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 Representations

Currently, the use of 'SweptSolid', 'Clipping' and 'MappedRepresentation' representations is supported. In addition the general representation types 'SurfaceModel', 'Brep', and 'BoundingBox' are allowed. The geometry use definition for 'BoundingBox', 'SurfaceModel' and 'Brep' is explained at IfcBuildingElement.

SweptSolid Representation

The standard geometric representation of IfcBeam is defined using the 'SweptSolid' representation. 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 shall be supported
- Profile: IfcRectangleProfileDef, IfcCircleProfileDef, IfcEllipseProfileDef, and IfcArbitraryClosedProfileDef (including the subtype IfcArbitraryProfileDefWithVoids) shall be supported, in addition the support of basic steel profiles, such as IfcIShapeProfileDef, IfcLShapeProfileDef, IfcUShapeProfileDef, IfcCShapeProfileDef, IfcZShapeProfileDef, and IfcTShapeProfileDef can be agreed.
- Extrusion: All extrusion directions shall be supported.

> EXAMPLE: standard geometric representation.

| The following interpretation of dimension parameter applies for rectangular beams: IfcRectangleProfileDef.YDim interpreted as beam width IfcRectangleProfileDef.XDim interpreted as beam depth The following interpretation of dimension parameter applies for circular beams: IfcCircleProfileDef.Radius interpreted as beam radius.
| Use of non-perpendicular extrusion to create the IfcExtrudedAreaSolid.

Clipping Representation

The advanced geometric representation of IfcBeam is defined using the 'Clipping' geometry. 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 (or its subtypes).

> EXAMPLE advanced geometric representation

| Use of IfcBooleanClippingResult between an IfcExtrudedAreaSolid and an IfcHalfSpaceSolid to create a clipped body.

MappedRepresentation

In addition to the standard and advanced geometric representation of IfcBeam that is defined using the SweptSolid or Clipping geometry, also the MappedRepresentation, shall be 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' and 'Clipping' geometric representation, shall apply to the MappedRepresentation of the IfcRepresentationMap.

##### Inherited definitions from supertypes

Entity inheritance
Attribute inheritance

# | Attribute | Type | Cardinality | Description | A
--- | --- | --- | --- | --- | ---
IfcRoot
1 | GlobalId | IfcGloballyUniqueId | [1:1] | Assignment of a globally unique identifier within the entire software world. | X
2 | OwnerHistory | IfcOwnerHistory | [1:1] | Assignment of the information about the current ownership of that object, including owning actor, application, local identification and information captured about the recent changes of the object, NOTE: only the last modification in stored. | X
3 | Name | IfcLabel | [0:1] | Optional name for use by the participating software systems or users. For some subtypes of IfcRoot the insertion of the Name attribute may be required. This would be enforced by a where rule. | X
4 | Description | IfcText | [0:1] | Optional description, provided for exchanging informative comments. | X
IfcObjectDefinition
| IsDecomposedBy | IfcRelDecomposes @RelatingObject | S[0:?] | Reference to the decomposition relationship, that allows this object to be the composition of other objects. An object can be decomposed by several other objects. | X
| Decomposes | IfcRelDecomposes @RelatedObjects | S[0:1] | References to the decomposition relationship, that allows this object to be a part of the decomposition. An object can only be part of a single decomposition (to allow hierarchical strutures only). | X
| HasAssociations | IfcRelAssociates @RelatedObjects | S[0:?] | Reference to the relationship objects, that associates external references or other resource definitions to the object.. Examples are the association to library, documentation or classification. | X
IfcObject
5 | ObjectType | IfcLabel | [0:1] | The type denotes a particular type that indicates the object further. The use has to be established at the level of instantiable subtypes. In particular it holds the user defined type, if the enumeration of the attribute PredefinedType is set to USERDEFINED. | X
| IsDefinedBy | IfcRelDefines @RelatedObjects | S[0:?] | Set of relationships to type or property (statically or dynamically defined) information that further define the object. In case of type information, the associated IfcTypeObject contains the specific information (or type, or style), that is common to all instances of IfcObject referring to the same type. | X
IfcProduct
6 | ObjectPlacement | IfcObjectPlacement | [0:1] | Placement of the product in space, the placement can either be absolute (relative to the world coordinate system), relative (relative to the object placement of another product), or constraint (e.g. relative to grid axes). It is determined by the various subtypes of IfcObjectPlacement, which includes the axis placement information to determine the transformation for the object coordinate system. | X
7 | Representation | IfcProductRepresentation | [0:1] | Reference to the representations of the product, being either a representation (IfcProductRepresentation) or as a special case a shape representations (IfcProductDefinitionShape). The product definition shape provides for multiple geometric representations of the shape property of the object within the same object coordinate system, defined by the object placement. | X
IfcElement
8 | Tag | - |  | This attribute is out of scope for this model view definition and shall not be set. |
| ConnectedTo | IfcRelConnectsElements @RelatingElement | S[0:?] | Reference to the element connection relationship. The relationship then refers to the other element to which this element is connected to. |
| HasOpenings | IfcRelVoidsElement @RelatingBuildingElement | S[0:?] | Reference to the Voids Relationship that creates an opening in an element. An element can incorporate zero-to-many openings. | X
| IsConnectionRealization | IfcRelConnectsWithRealizingElements @RealizingElements | S[0:?] | Reference to the connection relationship with realizing element. The relationship then refers to the realizing element which provides the physical manifestation of the connection relationship. | X
| ConnectedFrom | IfcRelConnectsElements @RelatedElement | S[0:?] | Reference to the element connection relationship. The relationship then refers to the other element that is connected to this element. | X
| ContainedInStructure | IfcRelContainedInSpatialStructure @RelatedElements | S[0:1] | Containment relationship to the spatial structure element, to which the element is primarily associated. | X
IfcBuildingElement
IfcBeam

##### Definitions applying to AISC Model View

Instance diagram

A piece is major element of an assembly and is mapped to different IFC entity data types (IfcMember, IfcColumn, or IfcBeam) for its represenation depending on its position. Column is for a vertical steel element, Beam is for a horizontal steel member, and Member is for a diagonally placed element. There can be multiple pieces in an assembly, and one main piece that is identifed by a property attribute.

A piece may have attributes listed below should use Defines By Property Set (IfcRelDefinesByPropertyies) in order to represent required information items listed below and are described in the corresponding sections of this document.

Piece Identification

- GUID
- Part name
- Piece mark
- Indication mark
- Main piece tag
- Prelim mark
- Bar code

Material Information

- Material class
- Material ID
- Material certification
- Material grade
- Material type

Status Information

- Status flags

Version

- Version number

Quantity Information

- Count

Finish/ Treatment

- Surface treatment

Tolerance for Layout

- Tolerance

Castellation

- Castellation type
- Castellation End Post Width 1
- Castellation End Post Width 2
- Castellation spacing
- Castellation height
- Castellation width
- Castellation depth

Information Item Mapping

Steel Detailing Information | IFC Entity\Attribute | Note
Host Assembly | IfcRelAggregates |
Critical end point | IfcDiscreteAccessory \ Representation |
Angle of end cuts | IfcOpeningElement \ Representation |
Location in Assembly | IfcProduct \ ObjectPlacement |
Profile | IfcParameterizedProfileDef |
Length | IfcExtrudedAreaSolid \ Depth |

Concept usage

Properties on Occurrences

The Properties on Occurrences concept applies to this entity as shown in Table 9.

Property
AISC_EM11_Pset_PieceIdentification
AISC_EM11_Pset_ToleranceForLayout
AISC_EM11_Pset_Castellation
AISC_EM11_Pset_Material
AISC_EM11_Pset_StatusInformation
AISC_EM11_Pset_VersionInformation
Table 9 — IfcBeam Properties on Occurrences

Exchange |
--- | ---
Import | O
Export | O

Placement

The Placement concept applies to this entity.

Exchange |
--- | ---
Import | R
Export | R

Geometry

The Geometry concept applies to this entity.

Concept alternates

Body Geometry

The Body Geometry concept applies to this entity.

Exchange |
--- | ---
Import | R
Export | R

Concept alternates

Body Profile Extruded Area Solid

The Body Profile Extruded Area Solid concept applies to this entity.

Exchange |
--- | ---
Import | O
Export | O

Body Brep Geometry PolyLoop

The Body Brep Geometry PolyLoop concept applies to this entity.

Exchange |
--- | ---
Import | O
Export | O

Mapped Geometry

The Mapped Geometry concept applies to this entity.

Exchange |
--- | ---
Import | O
Export | O

Feature Substraction

The Feature Substraction concept applies to this entity as shown in Table 10.

FeatureObjectType | Description
--- | ---
BoltHole | Represents an instance of Bolt Hole
SlotHole | Represents an instance of a Slot Hole
Cope | Represents an instance of a Cope
Opening | Represents an instance of an Opening
SkewedEnd | Represents an instance of a Skewed End, which has two axis of rotation
WeldPreparation | Represents an instance of a Weld Preparation
TubeChamfer | Represents an instance of a Tube Chamfer
TubeSaddle | Represents an instance of a Tube Saddle
TubeEdgeSaddle | Represents an instance of a Tube Edge Saddle
TubeCrossingSaddle | Represents an instance of a Tube Crossing Saddle
TubeHoleSetIn | Represents an instance of a Tube Hole Set In
TubeHoleSetOut | Represents an instance of a Tube Hole Set Out
TubeMitreHole | Represents an instance of a Tube Hole Mitre Hole
TubeMitreSaddle | Represents an instance of a Tube Hole Mitre Saddle
TubeOblongHole | Represents an instance of a Tube Oblong Hole
TubeOffshoreSaddle | Represents an instance of a Tube Offshore Saddle
TubeOffshoreChamfer | Represents an instance of a Tube Offshore Chamfer
Table 10 — IfcBeam Feature Substraction

Exchange |
--- | ---
Import | O
Export | O

Element Decomposition

The Element Decomposition concept applies to this entity as shown in Table 11.

RelatedObjects | Description
--- | ---
IfcPlate | Represents each plate for 3-Plate structural piece
Table 11 — IfcBeam Element Decomposition

W or I shaped structural steel piece (column, beam or member) can be assembled with plates or discreet accessories. IfcRelAggregate\RelatedObject should refer to IfcBeam, IfcColumn or IfcMember, and IfcRelAggregate\RelatedObject should refer to IfcPlate

Exchange |
--- | ---
Import | O
Export | O

Material Solid

The Material Solid concept applies to this entity.

Exchange |
--- | ---
Import | O
Export | O

Quantities on Occurrences

The Quantities on Occurrences concept applies to this entity as shown in Table 12.

Qset | Quantity | Description
--- | --- | ---
AISC_EM11_Qto_Quantity | SameTypeCount | Number of assemblies with same assembly mark. Used on occuerrence, even though it should be used for type count for implementation convenience
Table 12 — IfcBeam Quantities on Occurrences

Exchange |
--- | ---
Import | O
Export | O

Concept inheritance

# | Concept | Model View
--- | --- | ---
IfcBeam
| Properties on Occurrences | AISC Model View
| Placement | AISC Model View
| Geometry | AISC Model View
| Feature Substraction | AISC Model View
| Element Decomposition | AISC Model View
| Material Solid | AISC Model View
| Quantities on Occurrences | AISC Model View

##### Formal representations

XSD Specification
`<xs:element name="IfcBeam" type="ifc:IfcBeam" substitutionGroup="ifc:IfcBuildingElement" nillable="true"/>
<xs:complexType name="IfcBeam">
<xs:complexContent>
<xs:extension base="ifc:IfcBuildingElement"/>
</xs:complexContent>
</xs:complexType>
`
EXPRESS Specification
`ENTITY IfcBeam
SUBTYPE OF (IfcBuildingElement);
END_ENTITY;

EXPRESS-G diagram

`

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