IfcIShapeProfileDef

Natural language names
I-Profil - parametrische Definition
IShape Profile Def
Définition de section d'un profil en I
Change log
ItemSPFXMLChangeDescription
IFC2x3 to IFC4
    IfcIShapeProfileDef
      PositionMODIFIEDInstantiation changed to OPTIONAL.
      FilletRadiusMODIFIEDType changed from IfcPositiveLengthMeasure to IfcNonNegativeLengthMeasure.
      FlangeEdgeRadiusADDED
      FlangeSlopeADDED
Semantic definitions at the entity
Entity definition

IfcIShapeProfileDef defines a section profile that provides the defining parameters of an 'I' or 'H' section. The I-shape profile has values for its overall depth, width and its web and flange thicknesses. Additionally a fillet radius, flange edge radius, and flange slope may be given. This profile definition represents an I-section which is symmetrical about its major and minor axes; top and bottom flanges are equal and centred on the web.

HISTORY  New entity in IFC2x.
IFC4 CHANGE  Type of FilletRadius relaxed to allow for zero radius. Attributes FlangeEdgeRadius and FlangeSlope added.

Figure 422 illustrates parameters of the I-shape profile definition.

I-shape profile

Position
The parameterized profile defines its own position coordinate system. The underlying coordinate system is defined by the swept area solid that uses the profile definition. It is the xy plane of:

  • IfcSweptAreaSolid.Position
by using offsets of the position location, the parameterized profile can be positioned centric (using x,y offsets = 0.), or at any position relative to the profile. Explicit coordinate offsets are used to define cardinal points (e.g. upper-left bound).

Parameter
The parameterized profile is defined by a set of parameter attributes, see attribute definition below.

I shape with fillet
Note: The black coordinate axes show the underlying coordinate system of the swept surface or swept area solid

Position
The profile is inserted into the underlying coordinate system of the swept area solid by using the Position attribute. In this example (cardinal point of lower left corner) the attribute values of IfcAxis2Placement2D are:

Location = IfcCartesianPoint(<1/2 OverallWidth>,<1/2 OverallDepth>)
RefDirection = NIL (defaults to 1.,0.)

Parameter
If the FilletRadius is given, it is equally applied to all four corners created by the web and flanges.

Figure 422 — I-shape profile

Attribute definitions
#AttributeTypeCardinalityDescription G
4OverallWidthIfcPositiveLengthMeasure Total extent of the width, defined parallel to the x axis of the position coordinate system.X
5OverallDepthIfcPositiveLengthMeasure Total extent of the depth, defined parallel to the y axis of the position coordinate system.X
6WebThicknessIfcPositiveLengthMeasure Thickness of the web of the I-shape. The web is centred on the x-axis and the y-axis of the position coordinate system.X
7FlangeThicknessIfcPositiveLengthMeasure Flange thickness of the I-shape. Both, the upper and the lower flanges have the same thickness and they are centred on the y-axis of the position coordinate system.X
8FilletRadiusIfcNonNegativeLengthMeasure? The fillet between the web and the flange. 0 if sharp-edged, omitted if unknown.X
9FlangeEdgeRadiusIfcNonNegativeLengthMeasure? Radius of the lower edges of the top flange and the upper edges of the bottom flange. 0 if sharp-edged, omitted if unknown.X
10FlangeSlopeIfcPlaneAngleMeasure? Slope of the lower faces of the top flange and of the upper faces of the bottom flange. Non-zero in case of tapered flanges, 0 in case of parallel flanges, omitted if unknown.X
Formal Propositions
RuleDescription
ValidFlangeThicknessThe sum of flange thicknesses shall be less than the overall depth.
ValidWebThicknessThe web thickness shall be less then the flange width.
ValidFilletRadiusThe FilletRadius, if given, shall be within the range of allowed values.
Inherited definitions from supertypes
Entity inheritance IfcParameterizedProfileDef IfcProfileDef
Attribute inheritance
#AttributeTypeCardinalityDescriptionG
IfcProfileDef
1ProfileTypeIfcProfileTypeEnum Defines the type of geometry into which this profile definition shall be resolved, either a curve or a surface area. In case of curve the profile should be referenced by a swept surface, in case of area the profile should be referenced by a swept area solid.X
2ProfileNameIfcLabel? Human-readable name of the profile, for example according to a standard profile table. As noted above, machine-readable standardized profile designations should be provided in IfcExternalReference.ItemReference. X
HasExternalReferenceIfcExternalReferenceRelationship
@RelatedResourceObjects
S[0:?]Reference to external information, e.g. library, classification, or document information, which is associated with the profile.
IFC4 CHANGE New inverse attribute
X
HasPropertiesIfcProfileProperties
@ProfileDefinition
S[0:?]Additional properties of the profile, for example mechanical properties.
IFC4 CHANGE New inverse attribute
X
IfcParameterizedProfileDef
3PositionIfcAxis2Placement2D? Position coordinate system of the parameterized profile definition. If unspecified, no translation and no rotation is applied. X
IfcIShapeProfileDef
4OverallWidthIfcPositiveLengthMeasure Total extent of the width, defined parallel to the x axis of the position coordinate system.X
5OverallDepthIfcPositiveLengthMeasure Total extent of the depth, defined parallel to the y axis of the position coordinate system.X
6WebThicknessIfcPositiveLengthMeasure Thickness of the web of the I-shape. The web is centred on the x-axis and the y-axis of the position coordinate system.X
7FlangeThicknessIfcPositiveLengthMeasure Flange thickness of the I-shape. Both, the upper and the lower flanges have the same thickness and they are centred on the y-axis of the position coordinate system.X
8FilletRadiusIfcNonNegativeLengthMeasure? The fillet between the web and the flange. 0 if sharp-edged, omitted if unknown.X
9FlangeEdgeRadiusIfcNonNegativeLengthMeasure? Radius of the lower edges of the top flange and the upper edges of the bottom flange. 0 if sharp-edged, omitted if unknown.X
10FlangeSlopeIfcPlaneAngleMeasure? Slope of the lower faces of the top flange and of the upper faces of the bottom flange. Non-zero in case of tapered flanges, 0 in case of parallel flanges, omitted if unknown.X
Definitions applying to General Usage

Concept inheritance

#ConceptTemplateModel View
IfcProfileDef
Property Sets for ObjectsProperty Sets for ObjectsGeneral Usage
Examples
Formal representations
XML Specification
 <xs:element name="IfcIShapeProfileDef" type="ifc:IfcIShapeProfileDef" substitutionGroup="ifc:IfcParameterizedProfileDef" nillable="true"/>
 <xs:complexType name="IfcIShapeProfileDef">
  <xs:complexContent>
   <xs:extension base="ifc:IfcParameterizedProfileDef">
    <xs:attribute name="OverallWidth" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
    <xs:attribute name="OverallDepth" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
    <xs:attribute name="WebThickness" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
    <xs:attribute name="FlangeThickness" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
    <xs:attribute name="FilletRadius" type="ifc:IfcNonNegativeLengthMeasure" use="optional"/>
    <xs:attribute name="FlangeEdgeRadius" type="ifc:IfcNonNegativeLengthMeasure" use="optional"/>
    <xs:attribute name="FlangeSlope" type="ifc:IfcPlaneAngleMeasure" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcIShapeProfileDef
 SUBTYPE OF (IfcParameterizedProfileDef);
  OverallWidth : IfcPositiveLengthMeasure;
  OverallDepth : IfcPositiveLengthMeasure;
  WebThickness : IfcPositiveLengthMeasure;
  FlangeThickness : IfcPositiveLengthMeasure;
  FilletRadius : OPTIONAL IfcNonNegativeLengthMeasure;
  FlangeEdgeRadius : OPTIONAL IfcNonNegativeLengthMeasure;
  FlangeSlope : OPTIONAL IfcPlaneAngleMeasure;
 WHERE
  ValidFlangeThickness : (2. * FlangeThickness) < OverallDepth;
  ValidWebThickness : WebThickness < OverallWidth;
  ValidFilletRadius : NOT(EXISTS(FilletRadius)) OR
((FilletRadius <= (OverallWidth - WebThickness)/2.) AND
(FilletRadius <= (OverallDepth - (2. * FlangeThickness))/2.));
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

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