IfcSlabStandardCase

Item	SPF	XML	Change	Description
IFC2x3 to IFC4
IfcSlabStandardCase			ADDED

Rule	Description
HasMaterialLayerSetusage	A valid instance of IfcSlabStandardCase relies on the provision of an IfcMaterialLayerSetUsage.

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	C
IfcRoot
1	GlobalId	IfcGloballyUniqueId	[1:1]	Assignment of a globally unique identifier within the entire software world.	X
2	OwnerHistory	IfcOwnerHistory	[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
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
	HasAssignments	IfcRelAssigns @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
	Nests	IfcRelNests @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
	IsNestedBy	IfcRelNests @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
	HasContext	IfcRelDeclares @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
	IsDecomposedBy	IfcRelAggregates @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
	Decomposes	IfcRelAggregates @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
	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
	IsDeclaredBy	IfcRelDefinesByObject @RelatedObjects	S[0:1]	Link to the relationship object pointing to the declaring object that provides the object definitions for this object occurrence. The declaring object has to be part of an object type decomposition. The associated IfcObject, or its subtypes, contains the specific information (as part of a type, or style, definition), that is common to all reflected instances of the declaring IfcObject, or its subtypes.	X
	Declares	IfcRelDefinesByObject @RelatingObject	S[0:?]	Link to the relationship object pointing to the reflected object(s) that receives the object definitions. The reflected object has to be part of an object occurrence decomposition. The associated IfcObject, or its subtypes, provides the specific information (as part of a type, or style, definition), that is common to all reflected instances of the declaring IfcObject, or its subtypes.	X
	IsTypedBy	IfcRelDefinesByType @RelatedObjects	S[0:1]	Set of relationships to the object type that provides the type definitions for this object occurrence. The then associated IfcTypeObject, or its subtypes, contains the specific information (or type, or style), that is common to all instances of IfcObject, or its subtypes, referring to the same type.	X
	IsDefinedBy	IfcRelDefinesByProperties @RelatedObjects	S[0:?]	Set of relationships to property set definitions attached to this object. Those statically or dynamically defined properties contain alphanumeric information content that further defines the object.	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
	ReferencedBy	IfcRelAssignsToProduct @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.	X
IfcElement
8	Tag	IfcIdentifier	[0:1]	The tag (or label) identifier at the particular instance of a product, e.g. the serial number, or the position number. It is the identifier at the occurrence level.	X
	FillsVoids	IfcRelFillsElement @RelatedBuildingElement	S[0:1]	Reference to the IfcRelFillsElement Relationship that puts the element as a filling into the opening created within another element.	X
	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.	X
	IsInterferedByElements	IfcRelInterferesElements @RelatedElement	S[0:?]	Reference to the interference relationship to indicate the element that is interfered. The relationship, if provided, indicates that this element has an interference with one or many other elements. NOTE There is no indication of precedence between IsInterferedByElements and InterferesElements.	X
	InterferesElements	IfcRelInterferesElements @RelatingElement	S[0:?]	Reference to the interference relationship to indicate the element that interferes. The relationship, if provided, indicates that this element has an interference with one or many other elements. NOTE There is no indication of precedence between IsInterferedByElements and InterferesElements.	X
	HasProjections	IfcRelProjectsElement @RelatingElement	S[0:?]	Projection relationship that adds a feature (using a Boolean union) to the IfcBuildingElement.	X
	ReferencedInStructures	IfcRelReferencedInSpatialStructure @RelatedElements	S[0:?]	Reference relationship to the spatial structure element, to which the element is additionally associated. This relationship may not be hierarchical, an element may be referenced by zero, one or many spatial structure elements.	X
	HasOpenings	IfcRelVoidsElement @RelatingBuildingElement	S[0:?]	Reference to the IfcRelVoidsElement relationship that creates an opening in an element. An element can incorporate zero-to-many openings. For each opening, that voids the element, a new relationship IfcRelVoidsElement is generated.	X
	IsConnectionRealization	IfcRelConnectsWithRealizingElements @RealizingElements	S[0:?]	Reference to the connection relationship with realizing element. The relationship, if provided, assigns this element as the realizing element to the connection, which provides the physical manifestation of the connection relationship.	X
	ProvidesBoundaries	IfcRelSpaceBoundary @RelatedBuildingElement	S[0:?]	Reference to space boundaries by virtue of the objectified relationship IfcRelSpaceBoundary. It defines the concept of an element bounding spaces.	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. This containment relationship has to be hierachical, i.e. an element may only be assigned directly to zero or one spatial structure.	X
	HasCoverings	IfcRelCoversBldgElements @RelatingBuildingElement	S[0:?]	Reference to IfcCovering by virtue of the objectified relationship IfcRelCoversBldgElement. It defines the concept of an element having coverings associated.	X
IfcBuildingElement
IfcSlab
9	PredefinedType	IfcSlabTypeEnum	[0:1]	Predefined generic type for a slab that is specified in an enumeration. There may be a property set given specifically for the predefined types. NOTE The PredefinedType shall only be used, if no IfcSlabType is assigned, providing its own IfcSlabType.PredefinedType.	X
IfcSlabStandardCase

Definitions applying to Common Use Definitions

Instance diagram

Concept usage

Material Layer Set Usage

The Material Layer Set Usage concept applies to this entity.

Multi-layer slabs can be represented by refering to several IfcMaterialLayer's within the IfcMaterialLayerSet that is referenced from the IfcMaterialLayerSetUsage.

Material information can also be given at the IfcSlabType, defining the common attribute data for all occurrences of the same type. It is then accessible by the inverse IsDefinedBy relationship pointing to IfcSlabType.HasAssociations and via IfcRelAssociatesMaterial.RelatingMaterial. The IfcSlabStandardCase defines in addition that the IfcSlabType should have a unique IfcMaterialLayerSet, that is referenced by the IfcMaterialLayerSetUsage assigned to all occurrences of this IfcSlabType.

	EXAMPLE Figure 236 illustrates assignment of IfcMaterialLayerSetUsage and IfcMaterialLayerSet to the IfcSlabStandardCase as the slab occurrence and to the IfcSlabType. The same IfcMaterialLayerSet shall be shared by many occurrences of IfcMaterialLayerSetUsage. This relationship shall be consistent to the relationship between the IfcSlabType and the IfcSlabStandardCase.
Figure 236 — Slab type definition

Figure 237 illustrates slab material usage, where the following conventions shall be met:

The reference coordinate system is the coordinate system established by the IfcExtrudedAreaSolid.Position.
The reference plane is the plane defined by the extruded profile of IfcExtrudedAreaSolid.SweptSolid. The IfcMaterialLayerSetUsage.OffsetFromReferenceLine is given as a distance from this plane.
The IfcMaterialLayerSetUsage.DirectionSense defines how the IfcMaterialLayer's are assigned to the reference plane. POSITIVE means in direction to the positive z-axis of the reference coordinate system.
The IfcMaterialLayerSetUsage.OffsetFromReferenceLine is the distance parallel to the reference plane and always perpendicular to the base (XY) plane of the reference coordinate system. This is independent of a potential non-perpendicular extrusion given by IfcExtrudedAreaSolid.ExtrudedDirection <> 0.,0.,1. A positive value of IfcMaterialLayerSetUsage.OffsetFromReferenceLine would then point into the positive z-axis of the reference coordinate system.
The Thickness of each IfcMaterialLayer shall be the parallel distance (measured perpendicular to the base plane). The TotalThickness of the IfcMaterialLayerSet is the sum of all layer thicknesses and in case of a perpendicular extrusion identical with IfcExtrudedAreaSolid.Depth
The IfcMaterialLayerSetUsage.LayerSetDirection is always AXIS3.

Figure 237 — Slab material layers

Product Local Placement

The Product Local Placement concept applies to this entity as shown in Table 171.

Type	Relative	Description
IfcLocalPlacement	IfcLocalPlacement	Relative placement according to position and rotation relative to container.
IfcLocalPlacement		Absolute placement according to position and rotation of world coordinate system.
IfcGridPlacement		Placement according to grid intersection.

Table 171 — IfcSlabStandardCase Product Local Placement

The following restriction is imposed:

The local placement shall provide the location and directions for the standard slab, the x/y plane is the plane for the profile, and the z-axis is the extrusion axis for the slab body.

Body SweptSolid Geometry

The Body SweptSolid Geometry concept applies to this entity.

The following additional constraints apply to the swept solid representation:

Solid: IfcExtrudedAreaSolid is required,
Profile: IfcArbitraryClosedProfileDef, IfcRectangleProfileDef, IfcCircleProfileDef, IfcEllipseProfileDef shall be supported.
Extrusion: The profile can be extruded perpendicularly or non-perpendicularly to the plane of the swept profile.
Material: The definition of the IfcMaterialLayerSetUsage, particularly of the OffsetFromReferenceLine and the ForLayerSet.TotalThickness, has to be consistent to the 'SweptSolid' representation.

	EXAMPLE Figure 237 illustrates a 'SweptSolid' geometric representation. The following interpretation of dimension parameter applies for polygonal slabs (in ground floor view): IfcArbitraryClosedProfileDef.OuterCurve: closed bounded curve interpreted as area (or foot print) of the slab.
Figure 237 — Slab body extrusion

Body Clipping Geometry

The Body Clipping Geometry concept applies to this entity.

The following constraints apply to the 'Clipping' representation:

Solid: see 'SweptSolid' shape representation,
Profile: see 'SweptSolid' shape representation,
Extrusion: see 'SweptSolid' shape representation,
Material: see 'SweptSolid' shape representation,
Boolean result: The IfcBooleanClippingResult shall be supported, allowing for Boolean differences between the swept solid (here IfcExtrudedAreaSolid) and one or several IfcHalfSpaceSolid.

	EXAMPLE Figure 238 illustrates a 'Clipping' geometric representation with definition of a roof slab using advanced geometric representation. The profile is extruded non-perpendicular and the slab body is clipped at the eave.
Figure 238 — Slab body clipping

Concept inheritance

#	Concept	Model View
IfcRoot
	Software Identity	Common Use Definitions
	Revision Control	Common Use Definitions
IfcObject
	Object Occurrence Predefined Type	Common Use Definitions
IfcElement
	Box Geometry	Common Use Definitions
	FootPrint Geometry	Common Use Definitions
	Body SurfaceOrSolidModel Geometry	Common Use Definitions
	Body SurfaceModel Geometry	Common Use Definitions
	Body Tessellation Geometry	Common Use Definitions
	Body Brep Geometry	Common Use Definitions
	Body AdvancedBrep Geometry	Common Use Definitions
	Body CSG Geometry	Common Use Definitions
	Mapped Geometry	Common Use Definitions
	Mesh Geometry	Common Use Definitions
IfcBuildingElement
	Surface 3D Geometry	Common Use Definitions
IfcSlab
	Object Typing	Common Use Definitions
	Property Sets for Objects	Common Use Definitions
	Quantity Sets	Common Use Definitions
	Material Layer Set	Common Use Definitions
	Spatial Containment	Common Use Definitions
	Surface Geometry	Common Use Definitions
	Element Voiding	Common Use Definitions
	Product Assignment	Common Use Definitions
IfcSlabStandardCase
	Material Layer Set Usage	Common Use Definitions
	Product Local Placement	Common Use Definitions
	Body SweptSolid Geometry	Common Use Definitions
	Body Clipping Geometry	Common Use Definitions

Examples

Formal representations

XSD Specification

 <xs:element name="IfcSlabStandardCase" type="ifc:IfcSlabStandardCase" substitutionGroup="ifc:IfcSlab" nillable="true"/>

 <xs:complexType name="IfcSlabStandardCase">

  <xs:complexContent>

   <xs:extension base="ifc:IfcSlab"/>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcSlabStandardCase

 SUBTYPE OF (IfcSlab);

 WHERE

  HasMaterialLayerSetusage : SIZEOF (QUERY(temp <* USEDIN(SELF, 'IFCKERNEL.IFCRELASSOCIATES.RELATEDOBJECTS') |
              ('IFCPRODUCTEXTENSION.IFCRELASSOCIATESMATERIAL' IN TYPEOF(temp)) AND
              ('IFCMATERIALRESOURCE.IFCMATERIALLAYERSETUSAGE' IN TYPEOF(temp.RelatingMaterial))
              )) = 1;
END_ENTITY;

 EXPRESS-G diagram

Link to this page

	Decke / Dachfläche / Bodenplatte - Standard
	Slab Standard Case
	Dalle standard

IfcSlabStandardCase

Semantic definitions at the entity

Inherited definitions from supertypes

Definitions applying to Common Use Definitions

Examples

Formal representations