|Platte / Paneel - Standard|
The standard plate,
IfcPlateStandardCase, defines a plate with certain
constraints for the provision of material usage, parameters and
with certain constraints for the geometric representation. The
IfcPlateStandardCase handles all cases of plates, that:
- have a reference to the IfcMaterialLayerSetUsage
defining the material layers of the plate with thicknesses
- are based on an extrusion of a planar surface as defined by the
- have a constant thickness along the extrusion direction
- are consistent in using the correct material layer set offset
to the base planar surface in regard to the shape
- are extruded perpendicular to the plane surface
The definitions of plate openings and niches are the same as
given at the supertype IfcPlate. The same agreements to the
special types of plates, as defined in the PredefinedType
attribute apply as well.
HISTORY New entity in IFC4.
Common Use Definitions
The following concepts are inherited at supertypes:
- IfcRoot: Identity, Revision Control
- IfcElement: Box Geometry, FootPrint Geometry, Body SurfaceOrSolidModel Geometry, Body SurfaceModel Geometry, Body Tessellation Geometry, Body Brep Geometry, Body AdvancedBrep Geometry, Body CSG Geometry, Mapped Geometry
- IfcPlate: Object Typing, Property Sets for Objects, Quantity Sets, Material Layer Set, Spatial Containment, Surface 3D Geometry, Product Assignment
Material Layer Set Usage
The Material Layer Set Usage concept applies to this entity.
The material of the IfcPlateStandardCase is defined by
IfcMaterialLayerSetUsage and attached by the
IfcRelAssociatesMaterial.RelatingMaterial. It is
accessible by the inverse HasAssociations relationship.
Multi-layer plates can be represented by refering to several
IfcMaterialLayer's within the IfcMaterialLayerSet
that is referenced from the
Material information can also be given at the
IfcPlateType, defining the common attribute data for all
occurrences of the same type. It is then accessible by the
inverse IsDefinedBy relationship pointing to
IfcPlateType.HasAssociations and via
The IfcPlateStandardCase defines in addition that the
IfcPlateType should have a unique
IfcMaterialLayerSet, that is referenced by
the IfcMaterialLayerSetUsage assigned to all
occurrences of this IfcPlateType.
Figure 196 illustrates assignment of IfcMaterialLayerSetUsage and IfcMaterialLayerSet to the IfcPlateStandardCase as the plate occurrence and to the IfcPlateType. The same IfcMaterialLayerSet shall be shared by many occurrences of IfcMaterialLayerSetUsage. This relationship shall be consistent to the relationship between the IfcPlateType and the IfcPlateStandardCase.
Figure 196 — Plate type definition
As shown in Figure 106, 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 i always AXIS3.
Figure 197 — Plate material layers
The Product Placement concept applies to this entity as shown in Table 140.
Table 140 — IfcPlateStandardCase Product Placement
The following restriction is imposed:
- The local placement shall provide the location and directions
for the standard plate, the x/y plane is the plane for the
profile, and the z-axis is the extrusion axis for the plate body.
Body SweptSolid Geometry
The Body SweptSolid Geometry concept applies to this entity.
The following additional constraints apply to the swept solid
- Solid: IfcExtrudedAreaSolid is required,
- Profile: IfcArbitraryClosedProfileDef,
IfcCircleProfileDef, IfcEllipseProfileDef shall be
- 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
EXAMPLE Figure 198 illustrates a 'SweptSolid' geometric representation. The following interpretation of dimension parameter applies for polygonal plates (in ground floor view): IfcArbitraryClosedProfileDef.OuterCurve being a closed bounded curve is interpreted as area (or foot print) of the plate.
Figure 198 — Plate body extrusion
Body Clipping Geometry
The Body Clipping Geometry concept applies to this entity.
The following constraints apply to the 'Clipping'
- Solid: see 'SweptSolid' shape representation,
- Profile: see 'SweptSolid' shape
- Extrusion: see 'SweptSolid' shape
- Material: see 'SweptSolid' shape
- Boolean result: The IfcBooleanClippingResult
shall be supported, allowing for Boolean differences between the
swept solid (here IfcExtrudedAreaSolid) and one or several
EXAMPLE Figure 199 illustrates a 'Clipping' geometric representation with definition of a plate using advanced geometric representation. The profile is extruded non-perpendicular and the plate body is clipped at the eave.
Figure 199 — Plate body clipping
XSD Specification: <xs:element name="IfcPlateStandardCase" type="ifc:IfcPlateStandardCase" substitutionGroup="ifc:IfcPlate" nillable="true"/>
|HasMaterialLayerSetUsage|| : ||SIZEOF (QUERY(temp <* USEDIN(SELF, 'IFCKERNEL.IFCRELASSOCIATES.RELATEDOBJECTS') |
('IFCPRODUCTEXTENSION.IFCRELASSOCIATESMATERIAL' IN TYPEOF(temp)) AND
('IFCMATERIALRESOURCE.IFCMATERIALLAYERSETUSAGE' IN TYPEOF(temp.RelatingMaterial))
)) = 1;|
|HasMaterialLayerSetUsage|| : ||
A valid instance of IfcPlateStandardCase relies on the provision of an IfcMaterialLayerSetUsage.
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