Sich verjüngender Festkörper - aus extrudierter Fläche

IfcExtrudedAreaSolidTapered is defined by sweeping a cross section along a linear spine. The cross section may change along the sweep from the shape of the start cross section into the shape of the end cross section. The resulting solid is bounded by three or more faces: A start face, an end face (each defined by start and end planes and sections), and one or more lateral faces. Each lateral face is a ruled surface defined by a pair of corresponding edges of the start and end section.

NOTE  Given that the start and end section is provided by a polygon, the corresponding vertices of the start and end cross section are connected, forming a quadrilateral polygon between each pair of corresponding vertices. The surface defined by the bounding quadrilateral polygon is a ruled surface, that could be approximated by triangulation.

The linear spine is defined by:

The start cross section is defined by SELF\IfcSweptAreaSolid.SweptArea:

The end cross section is defined by EndSweptArea:

In case of two parameterized profiles the shape is constructed as follows:

In case of Cartesian transformation of the start cross section the shape is constructed as follows:

HISTORY  New entity in IFC4.

Informal Propositions:

  1. Mirroring within IfcDerivedProfileDef.Operator shall not be used

XSD Specification:

 <xs:element name="IfcExtrudedAreaSolidTapered" type="ifc:IfcExtrudedAreaSolidTapered" substitutionGroup="ifc:IfcExtrudedAreaSolid" nillable="true"/>
 <xs:complexType name="IfcExtrudedAreaSolidTapered">
   <xs:extension base="ifc:IfcExtrudedAreaSolid">
     <xs:element name="EndSweptArea" type="ifc:IfcProfileDef" nillable="true"/>

EXPRESS Specification:

ENTITY IfcExtrudedAreaSolidTapered
SUBTYPE OF IfcExtrudedAreaSolid;
EndSweptArea : IfcProfileDef;
CorrectProfileAssignment : IfcTaperedSweptAreaProfiles(SELF\IfcSweptAreaSolid.SweptArea, SELF.EndSweptArea);

Link to EXPRESS-G diagram EXPRESS-G diagram

Attribute Definitions:

EndSweptArea : The surface defining the end of the swept area. It is given as a profile definition. The position coordinate system of the EndSwptArea is generated by translating the SELF\IfcSweptAreaSolid.Position along the SELF\IfcExtrudedAreaSolid.ExtrudedDirection by the distance of SELF\IfcExtrudedAreaSolid.Depth.

Formal Propositions:

CorrectProfileAssignment : The SweptArea as start profile and the EndSweptArea as end profile shall be compatible.

Inheritance Graph:

ENTITY IfcExtrudedAreaSolidTapered
ENTITY IfcRepresentationItem
LayerAssignment : SET [0:1] OF IfcPresentationLayerAssignment FOR AssignedItems;
StyledByItem : SET [0:1] OF IfcStyledItem FOR Item;
ENTITY IfcGeometricRepresentationItem
ENTITY IfcSolidModel
Dim : IfcDimensionCount := 3;
ENTITY IfcSweptAreaSolid
SweptArea : IfcProfileDef;
Position : OPTIONAL IfcAxis2Placement3D;
ENTITY IfcExtrudedAreaSolid
ExtrudedDirection : IfcDirection;
Depth : IfcPositiveLengthMeasure;
ENTITY IfcExtrudedAreaSolidTapered
EndSweptArea : IfcProfileDef;


Link to this page  Link to this page