#### 6.1.3.4 IfcPlate

| Platte / Paneel
| Plaque

An IfcPlate is a planar and often flat part with constant thickness. A plate may carry loads between or beyond points of support, or provide stiffening. The location of the plate (being horizontal, vertical or sloped) is not relevant to its definition (in contrary to IfcWall and IfcSlab (as floor slab)).

> NOTE Definition according to ISO 6707-1: thin, rigid, flat, metal product, of a thickness greater than that of a sheet.

Plates are normally made of steel, other metallic material, or by glass panels. However the definition of IfcPlate is material independent and specific material information shall be handled by using IfcAssociatesMaterial to assign a material specification to the IfcPlate.

> NOTE Although not necessarily, plates are often add-on parts. This is represented by the IfcRelAggregates decomposition mechanism used to aggregate parts, such as IfcPlate, into a container element such as IfcElementAssembly or IfcCurtainWall.

> NOTE The representation of a plate in a structural analysis model is provided by IfcStructuralSurfaceMember being part of an IfcStructuralAnalysisModel.

An instance IfcPlate should preferably get its geometric representation and material assignment through the type definition by IfcPlateType assigned using the IfcRelDefinesByType relationship. This allows identical plates in a construction to be represented by the same instance of IfcPlateType.

A plate may have openings, such as voids or recesses. They are defined by an IfcOpeningElement attached to the plate using the inverse relationship HasOpenings pointing to IfcRelVoidsElement. The position number of a plate as often used in steel construction is assigned through the attribute IfcElement.Tag

The IFC specification provides two entities for plate occurrences:

- IfcPlateStandardCase used for all occurrences of plates, that are prismatic and where the thickness parameter can be fully described by the IfcMaterialLayerSetUsage. These plates are always represented geometrically by a 'SweptSolid' geometry (or by a 'Clipping' geometry based on 'SweptSolid'), if a 3D geometric representation is assigned. In addition they have to have a corresponding IfcMaterialLayerSetUsage assigned.
- IfcPlate used for all other occurrences of plates, particularly for plates with changing thickness, or plates with non planar surfaces, and plates having only 'SurfaceModel' or 'Brep' geometry.

> HISTORY New entity in IFC2x2

Geometric Representation

Currently, the 'Surface', 'FootPrint', 'Body', and 'Box' representations are supported. The 'Box' representation includes the representation type 'BoundingBox' and is explained at IfcBuildingElement.

XSD Specification:

<xs:element name="IfcPlate" type="ifc:IfcPlate" substitutionGroup="ifc:IfcBuildingElement" nillable="true"/>
<xs:complexType name="IfcPlate">
<xs:complexContent>
<xs:extension base="ifc:IfcBuildingElement"/>
</xs:complexContent>
</xs:complexType>

EXPRESS Specification:

ENTITY IfcPlate

| SUBTYPE OF (IfcBuildingElement);

PredefinedType | : | OPTIONAL IfcStrippedOptional;

| WHERE

CorrectPredefinedType | : | NOT(EXISTS(PredefinedType)) OR (PredefinedType <> IfcPlateTypeEnum.USERDEFINED) OR ((PredefinedType = IfcPlateTypeEnum.USERDEFINED) AND EXISTS (SELF\IfcObject.ObjectType));
CorrectTypeAssigned | : | (SIZEOF(IsTypedBy) = 0) OR ('IFCSHAREDBLDGELEMENTS.IFCPLATETYPE' IN TYPEOF(SELF\IfcObject.IsTypedBy[1].RelatingType));

END_ENTITY;

Attribute Definitions:

Formal Propositions:

CorrectPredefinedType | : | Either the PredefinedType attribute is unset (e.g. because an IfcPlateType is associated), or the inherited attribute ObjectType shall be provided, if the PredefinedType is set to USERDEFINED.
CorrectTypeAssigned | : | Either there is no plate type object associated, i.e. the IsTypedBy inverse relationship is not provided, or the associated type object has to be of type IfcPlateType.

Inheritance Graph:

ENTITY IfcPlate

| 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 IfcObject

ObjectType | : | OPTIONAL IfcStrippedOptional;

| INVERSE

IsDeclaredBy | : | SET [0:1] OF IfcRelDefinesByObject FOR RelatedObjects;
Declares | : | SET OF IfcRelDefinesByObject FOR RelatingObject;
IsTypedBy | : | SET [0:1] OF IfcRelDefinesByType FOR RelatedObjects;
IsDefinedBy | : | SET OF IfcRelDefinesByProperties FOR RelatedObjects;

| ENTITY IfcProduct

ObjectPlacement | : | OPTIONAL IfcObjectPlacement;
Representation | : | OPTIONAL IfcProductRepresentation;

| INVERSE

ReferencedBy | : | SET OF IfcRelAssignsToProduct FOR RelatingProduct;

| ENTITY IfcElement

Tag | : | OPTIONAL IfcStrippedOptional;

| INVERSE

IsInterferedByElements | : | SET OF IfcRelInterferesElements FOR RelatedElement;
InterferesElements | : | SET OF IfcRelInterferesElements FOR RelatingElement;
ContainedInStructure | : | SET [0:1] OF IfcRelContainedInSpatialStructure FOR RelatedElements;

| ENTITY IfcBuildingElement

| INVERSE

| ENTITY IfcPlate

PredefinedType | : | OPTIONAL IfcStrippedOptional;

END_ENTITY;

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