6.1.3.41 IfcSlabType

Decke / Dachfläche / Bodenplatte - Typ
Type de dalle

The element type IfcSlabType defines commonly shared information for occurrences of slabs. The set of shared information may include:

NOTE  It is illegal to share shape representations as representation maps for occurrences of IfcSlabStandardCase.

It is used to define a slab specification (i.e. the specific product information, that is common to all occurrences of that product type). Slab types may be exchanged without being already assigned to occurrences.

NOTE  The product representations are defined as representation maps (at the level of the supertype IfcTypeProduct, which gets assigned by an element occurrence instance through the IfcShapeRepresentation.Item[1] being an IfcMappedItem.

The occurrences of the IfcSlabType within building models are represented by instances of IfcSlabStandardCase if the IfcSlabType has a single associated IfcMaterialLayerSet; otherwise they are represented by instances of IfcSlab, or IfcSlabElementedCase.

HISTORY  New entity in IFC2x2.

Informal Propositions:

  1. The material assignment, if provided using the IfcRelAssociatesMaterial relationship, shall not reference the IfcMaterialLayerSetUsage.

Common Use Definitions

The following concepts are inherited at supertypes:

 Instance diagram

Material Layer Set

The Material Layer Set concept applies to this entity.

The material of the IfcSlabType is defined by the IfcMaterialLayerSet 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 IfcSlabType, if there is at least one occurrences. of IfcSlabStandardCase for this type.

The shared material layer set definition is defined by assigning an IfcMaterialLayerSet (see material use definition above). The IfcMaterialLayer refers to one or several of IfcMaterial that is the common for all slab occurrence, if used. It is only applicable if the IfcSlabType has only occurrences of type IfcSlabStandardCase (see definition of IfcSlabStandardCase for further information).

NOTE  Since each individual instance of IfcSlabStandardCase defines its own IfcMaterialLayerSetUsage including the offset from the reference plane, the same IfcSlabType can be used independently of the reference plane alignment of its occurrences.


Type Body Geometry

The Type Body Geometry concept applies to this entity.




XSD Specification:

 <xs:element name="IfcSlabType" type="ifc:IfcSlabType" substitutionGroup="ifc:IfcBuildingElementType" nillable="true"/>
 <xs:complexType name="IfcSlabType">
  <xs:complexContent>
   <xs:extension base="ifc:IfcBuildingElementType">
    <xs:attribute name="PredefinedType" type="ifc:IfcSlabTypeEnum" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>

EXPRESS Specification:

ENTITY IfcSlabType
SUBTYPE OF IfcBuildingElementType;
PredefinedType : IfcSlabTypeEnum;
WHERE
CorrectPredefinedType : (PredefinedType <> IfcSlabTypeEnum.USERDEFINED) OR ((PredefinedType = IfcSlabTypeEnum.USERDEFINED) AND EXISTS(SELF\IfcElementType.ElementType));
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

Attribute Definitions:

PredefinedType : Identifies the predefined types of a slab element from which the type required may be set.

Formal Propositions:

CorrectPredefinedType : The inherited attribute ElementType shall be provided, if the PredefinedType is set to USERDEFINED.

Inheritance Graph:

ENTITY IfcSlabType
ENTITY IfcRoot
GlobalId : IfcGloballyUniqueId;
OwnerHistory : OPTIONAL IfcOwnerHistory;
Name : OPTIONAL IfcLabel;
Description : OPTIONAL IfcText;
ENTITY IfcObjectDefinition
INVERSE
HasAssignments : SET OF IfcRelAssigns FOR RelatedObjects;
Nests : SET [0:1] OF IfcRelNests FOR RelatedObjects;
IsNestedBy : SET OF IfcRelNests FOR RelatingObject;
HasContext : SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions;
IsDecomposedBy : SET OF IfcRelAggregates FOR RelatingObject;
Decomposes : SET [0:1] OF IfcRelAggregates FOR RelatedObjects;
HasAssociations : SET OF IfcRelAssociates FOR RelatedObjects;
ENTITY IfcTypeObject
ApplicableOccurrence : OPTIONAL IfcIdentifier;
HasPropertySets : OPTIONAL SET [1:?] OF IfcPropertySetDefinition;
INVERSE
Types : SET [0:1] OF IfcRelDefinesByType FOR RelatingType;
ENTITY IfcTypeProduct
RepresentationMaps : OPTIONAL LIST [1:?] OF UNIQUE IfcRepresentationMap;
Tag : OPTIONAL IfcLabel;
INVERSE
ReferencedBy : SET OF IfcRelAssignsToProduct FOR RelatingProduct;
ENTITY IfcElementType
ElementType : OPTIONAL IfcLabel;
ENTITY IfcBuildingElementType
ENTITY IfcSlabType
PredefinedType : IfcSlabTypeEnum;
END_ENTITY;

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