IfcIShapeProfileDef

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 295 illustrates parameters of the I-shape profile definition.

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.

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 295 — I-shape profile

Attribute definitions

#	Attribute	Type	Cardinality	Description	B
4	OverallWidth	IfcPositiveLengthMeasure	[1:1]	Total extent of the width, defined parallel to the x axis of the position coordinate system.	X
5	OverallDepth	IfcPositiveLengthMeasure	[1:1]	Total extent of the depth, defined parallel to the y axis of the position coordinate system.	X
6	WebThickness	IfcPositiveLengthMeasure	[1:1]	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
7	FlangeThickness	IfcPositiveLengthMeasure	[1:1]	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
8	FilletRadius	IfcNonNegativeLengthMeasure	[0:1]	The fillet between the web and the flange. 0 if sharp-edged, omitted if unknown.	X
9	FlangeEdgeRadius	IfcNonNegativeLengthMeasure	[0:1]	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
10	FlangeSlope	IfcPlaneAngleMeasure	[0:1]	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

Rule	Description
ValidFlangeThickness	The sum of flange thicknesses shall be less than the overall depth.
ValidWebThickness	The web thickness shall be less then the flange width.
ValidFilletRadius	The FilletRadius, if given, shall be within the range of allowed values.

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	B
IfcProfileDef
1	ProfileType	IfcProfileTypeEnum	[1:1]	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
2	ProfileName	IfcLabel	[0:1]	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
	HasProperties	IfcProfileProperties @ProfileDefinition	S[0:?]	Additional properties of the profile, for example mechanical properties.	X
IfcParameterizedProfileDef
3	Position	IfcAxis2Placement2D	[0:1]	Position coordinate system of the parameterized profile definition. If unspecified, no translation and no rotation is applied.	X
IfcIShapeProfileDef
4	OverallWidth	IfcPositiveLengthMeasure	[1:1]	Total extent of the width, defined parallel to the x axis of the position coordinate system.	X
5	OverallDepth	IfcPositiveLengthMeasure	[1:1]	Total extent of the depth, defined parallel to the y axis of the position coordinate system.	X
6	WebThickness	IfcPositiveLengthMeasure	[1:1]	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
7	FlangeThickness	IfcPositiveLengthMeasure	[1:1]	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
8	FilletRadius	IfcNonNegativeLengthMeasure	[0:1]	The fillet between the web and the flange. 0 if sharp-edged, omitted if unknown.	X
9	FlangeEdgeRadius	IfcNonNegativeLengthMeasure	[0:1]	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
10	FlangeSlope	IfcPlaneAngleMeasure	[0:1]	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 Bridge View

Concept inheritance

#	Concept	Model View
IfcProfileDef
	Property Sets for Objects	Bridge View

Formal representations

XSD 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;

 EXPRESS-G diagram

Link to this page

Item	Change	Description
IFC2x3 to IFC4
IfcIShapeProfileDef
Position	MODIFIED	Instantiation changed to OPTIONAL.
FilletRadius	MODIFIED	Type changed from IfcPositiveLengthMeasure to IfcNonNegativeLengthMeasure.
FlangeEdgeRadius	ADDED
FlangeSlope	ADDED

	I-Profil - parametrische Definition
	IShape Profile Def
	Définition de section d'un profil en I