IfcMemberType

Natural language names
deStab / Stabträger - Typ
enMember Type
frType de membre
Change log
ItemSPFXMLChangeDescription
IFC2x3 to IFC4
    IfcMemberType
      OwnerHistoryMODIFIEDInstantiation changed to OPTIONAL.
      ApplicableOccurrenceMODIFIEDType changed from IfcLabel to IfcIdentifier.
Semantic definitions at the entity
Entity definition

The element type IfcMemberType defines commonly shared information for occurrences of members. Members are predominately linear building elements, often forming part of a structural system. The orientation of the member (being horizontal, vertical or sloped) is not relevant to its definition (in contrary to beam and column). The set of shared information may include:

It is used to define a member specification, or member style (the specific product information that is common to all occurrences of that member type). Member types may be exchanged without being already assigned to occurrences.

Occurrences of the IfcMemberType within building models are represented by instances of IfcMemberStandardCase if the IfcMemberType has a single associated IfcMaterialProfileSet; otherwise they are represented by instances of IfcMember. Occurrences of the IfcMemberType within structural analysis models are represented by instances of IfcStructuralCurveMember, or its applicable subtypes.

HISTORY  New entity in IFC2x2 Addendum 1.
Attribute definitions
#AttributeTypeCardinalityDescription C
10PredefinedTypeIfcMemberTypeEnum[1:1] Identifies the predefined types of a linear structural member element from which the type required may be set.X
Formal Propositions
RuleDescription
CorrectPredefinedTypeThe inherited attribute ElementType shall be provided, if the PredefinedType is set to USERDEFINED.
Inherited definitions from supertypes
Entity inheritance IfcBuildingElementType IfcElementType IfcTypeProduct IfcTypeObject IfcObjectDefinition IfcRoot
Attribute inheritance
#AttributeTypeCardinalityDescriptionC
IfcRoot
1GlobalIdIfcGloballyUniqueId[1:1] Assignment of a globally unique identifier within the entire software world. X
2OwnerHistoryIfcOwnerHistory[0:1] 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 - either as addition, deletion or modification.
X
3NameIfcLabel[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
4DescriptionIfcText[0:1] Optional description, provided for exchanging informative comments.X
IfcObjectDefinition
HasAssignmentsIfcRelAssigns
@RelatedObjects		S[0:?]Reference to the relationship objects, that assign (by an association relationship) other subtypes of IfcObject to this object instance. Examples are the association to products, processes, controls, resources or groups.X
NestsIfcRelNests
@RelatedObjects		S[0:1]References to the decomposition relationship being a nesting. It determines that this object definition is a part within an ordered whole/part decomposition relationship. An object occurrence or type can only be part of a single decomposition (to allow hierarchical strutures only). X
IsNestedByIfcRelNests
@RelatingObject		S[0:?]References to the decomposition relationship being a nesting. It determines that this object definition is the whole within an ordered whole/part decomposition relationship. An object or object type can be nested by several other objects (occurrences or types). X
HasContextIfcRelDeclares
@RelatedDefinitions		S[0:1]References to the context providing context information such as project unit or representation context. It should only be asserted for the uppermost non-spatial object. X
IsDecomposedByIfcRelAggregates
@RelatingObject		S[0:?]References to the decomposition relationship being an aggregation. It determines that this object definition is whole within an unordered whole/part decomposition relationship. An object definitions can be aggregated by several other objects (occurrences or parts). X
DecomposesIfcRelAggregates
@RelatedObjects		S[0:1]References to the decomposition relationship being an aggregation. It determines that this object definition is a part within an unordered whole/part decomposition relationship. An object definitions can only be part of a single decomposition (to allow hierarchical strutures only). X
HasAssociationsIfcRelAssociates
@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
IfcTypeObject
5ApplicableOccurrenceIfcIdentifier[0:1] The attribute optionally defines the data type of the occurrence object, to which the assigned type object can relate. If not present, no instruction is given to which occurrence object the type object is applicable. The following conventions are used:
  • The IFC entity name of the applicable occurrence using the IFC naming convention, CamelCase with IFC prefix
  • It can be optionally followed by the predefined type after the separator "/" (forward slash), using uppercase
  • If one type object is applicable to many occurrence objects, then those occurrence object names should be separate by comma "," forming a comma separated string.
EXAMPLE Refering to a furniture as applicable occurrence entity would be expressed as 'IfcFurnishingElement', refering to a brace as applicable entity would be expressed as 'IfcMember/BRACE', refering to a wall and wall standard case would be expressed as 'IfcWall, IfcWallStandardCase'.
X
6HasPropertySetsIfcPropertySetDefinitionS[1:?] Set list of unique property sets, that are associated with the object type and are common to all object occurrences referring to this object type. X
TypesIfcRelDefinesByType
@RelatingType		S[0:1]Reference to the relationship IfcRelDefinedByType and thus to those occurrence objects, which are defined by this type.X
IfcTypeProduct
7RepresentationMapsIfcRepresentationMap~L[1:?] List of unique representation maps. Each representation map describes a block definition of the shape of the product style. By providing more than one representation map, a multi-view block definition can be given.X
8TagIfcLabel[0:1] The tag (or label) identifier at the particular type of a product, e.g. the article number (like the EAN). It is the identifier at the specific level.X
ReferencedByIfcRelAssignsToProduct
@RelatingProduct		S[0:?]Reference to the IfcRelAssignsToProduct relationship, by which other products, processes, controls, resources or actors (as subtypes of IfcObjectDefinition) can be related to this product type. X
IfcElementType
9ElementTypeIfcLabel[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
IfcBuildingElementType
IfcMemberType
10PredefinedTypeIfcMemberTypeEnum[1:1] Identifies the predefined types of a linear structural member element from which the type required may be set.X
Definitions applying to Common Use Definitions

 Instance diagram

Concept usage

Material Profile Set

The Material Profile Set concept applies to this entity.

The material of the IfcMemberType is defined by the IfcMaterialProfileSet or as fall back by IfcMaterial and attached by the IfcRelAssociatesMaterial.RelatingMaterial. It is accessible by the inverse HasAssociations relationship.

NOTE  It is illegal to assign an IfcMaterial to an IfcMemberType, if there is at least one occurrences of IfcMemberStandardCase for this type.

The shared profile definition is defined by assigning an IfcMaterialProfileSet (see material use definition above). The IfcMaterialProfile refers to the subtype of IfcProfileDef that is the common profile for all member occurrence, if used. It is only applicable if the IfcMemberType has only occurrences of type IfcMemberStandardCase (see definition of IfcMemberStandardCase for further information).

NOTE  The attribute ProfileName of the IfcProfileDef subtype, referenced in IfcMaterialProfile should contain a standardized profile name according to local standards. However, an additional geometric representation of the profile is necessary (e.g. as IfcExtrudedAreaSolid). An importing application is allowed to check for the existence of the profile name: in case of identifying it as a standardized name, the corresponding profile geometry and possibly other cross sectional properties can be read from a library. Otherwise the geometric representation and possible non geometric IfcProfileProperties have to be used.


Type Body Geometry

The Type Body Geometry concept applies to this entity.

The IfcMemberType may define the shared geometric representation for all member occurrences. The RepresentationMaps attribute refers to a list of IfcRepresentationMap's, that allow for multiple geometric representations (e.g. with IfcShaperepresentation's having an RepresentationIdentifier 'Box', 'Axis', or 'Body'). It is only applicable if the IfcMemberType has only occurrences of type IfcMember (See geometric use definition of IfcMember for further information).

NOTE  If the IfcMemberType has an associated IfcMaterialProfileSet, then no shared geometric representation shall be provided.
NOTE  The product shape representations are defined as RepresentationMaps (attribute of the supertype IfcTypeProduct), which get assigned by an element occurrence instance through the IfcShapeRepresentation.Item[n] being an IfcMappedItem. See IfcTypeProduct for further information.
NOTE  The values of attributes RepresentationIdentifier and RepresentationType of IfcShapeRepresentation are restricted in the same way as those for IfcMember and IfcMemberStandardCase


Concept inheritance

#ConceptModel View
IfcRoot
Software IdentityCommon Use Definitions
Revision ControlCommon Use Definitions
IfcTypeProduct
Product Type ShapeCommon Use Definitions
IfcMemberType
Material Profile SetCommon Use Definitions
Type Body GeometryCommon Use Definitions
Formal representations
XSD Specification
 <xs:element name="IfcMemberType" type="ifc:IfcMemberType" substitutionGroup="ifc:IfcBuildingElementType" nillable="true"/>
 <xs:complexType name="IfcMemberType">
  <xs:complexContent>
   <xs:extension base="ifc:IfcBuildingElementType">
    <xs:attribute name="PredefinedType" type="ifc:IfcMemberTypeEnum" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcMemberType
 SUBTYPE OF (IfcBuildingElementType);
  PredefinedType : IfcMemberTypeEnum;
 WHERE
  CorrectPredefinedType : (PredefinedType <> IfcMemberTypeEnum.USERDEFINED) OR ((PredefinedType = IfcMemberTypeEnum.USERDEFINED) AND EXISTS(SELF\IfcElementType.ElementType));
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

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