An IfcBeam is a horizontal, or nearly horizontal, structural member that is capable of withstanding load primarily by resisting bending. It represents such a member from an architectural point of view. It is not required to be load bearing. There are two main representations for beam occurrences:

• IfcBeam with IfcMaterialProfileSetUsage is used for all occurrences of beams, that have a profile defined that is swept along a directrix. The profile might change 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 geometrically 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.
• IfcBeam without IfcMaterialProfileSetUsage is used for all other occurrences of beams, particularly for beams with non-uniformly changing profile sizes along the sweep, or beams having only 'AdvancedBrep', 'Brep', or 'SurfaceModel' geometry, if a more parametric representation is not intended.

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

The Spatial Containment concept template applies to this entity as shown in table below:

The IfcBeam, as any subtype of IfcBuildingElement, can participate alternatively in one of the two different containment relationships:

• the Spatial Containment (defined here)
• the Element Composition.

The material of the IfcBeam is usually defined by the IfcMaterialProfileSet and it is attached either directly or at the IfcBeamType.

• It is illegal to assign an IfcMaterialProfileSetUsage to an IfcBeam. Only the subtype IfcBeamStandardCase supports this concept.

The Axis 3D Geometry concept template applies to this entity as shown in the table below:

The 'Axis' 'Curve 3D' geometry can be used to represent the system axis and length of a beam that can extent the body length. 

The following additional constraints apply to the 'SweptSolid' representation type: 

• Solid: IfcExtrudedAreaSolid, IfcRevolvedAreaSolid is supported
• Profile: all subtypes of IfcProfileDef (with exception of IfcArbitraryOpenProfileDef)
• Extrusion: All extrusion directions are supported
• Boolean result: The IfcBooleanClippingResult is supported, allowing for Boolean differences between the swept solid (here IfcExtrudedAreaSolid) and one or several IfcHalfSpaceSolid (or its subtypes).

The image below illustrates the '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). 

The image below illustrates the use of non-perpendicular extrusion to create the IfcExtrudedAreaSolid. 

The following additional constraints apply to the 'AdvancedSweptSolid' representation type:

• Solid: IfcSurfaceCurveSweptAreaSolid, IfcFixedReferenceSweptAreaSolid, IfcExtrudedAreaSolidTapered, IfcRevolvedAreaSolidTapered is be supported.
• Profile: see 'SweptSolid' geometric representation
• Extrusion: not applicable

The following additional constraints apply to the 'Clipping' representation type:

• Solid: see 'SweptSolid' geometric representation
• Profile: see 'SweptSolid' geometric representation
• Extrusion: see 'SweptSolid' geometric representation
• Boolean result: The IfcBooleanClippingResult is supported, allowing for Boolean differences between the swept solid (here IfcExtrudedAreaSolid) and one or several IfcHalfSpaceSolid (or its subtypes).

The image below illustrates use of IfcBooleanClippingResult between an IfcExtrudedAreaSolid and an IfcHalfSpaceSolid to create a clipped body. 

The entity IfcBeamStandardCase has been deleted in newer releases, IfcBeam with IfcMaterialProfileSetUsage is used instead. 

changes 

• IFC4X3_RC1 changes: Supertype changed from "IfcBuildingElement" to "IfcBuiltElement".