IFC 4.3.0.1 (IFC4X3) development

8.15.3.12 IfcIShapeProfileDef

8.15.3.12.1 Semantic 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.

Figure 8.15.3.12.B illustrates parameters of the I-shape profile definition.

I-shape profile
Figure 8.15.3.12.A

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:

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
Figure 8.15.3.12.B — I-shape profile

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.

8.15.3.12.2 Entity inheritance

8.15.3.12.3 Attributes

# Attribute Type Description
IfcProfileDef (4)
1 ProfileType IfcProfileTypeEnum

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.

2 ProfileName OPTIONAL IfcLabel

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.

HasExternalReference SET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjects

Reference to external information, e.g. library, classification, or document information, which is associated with the profile.

HasProperties SET [0:?] OF IfcProfileProperties FOR ProfileDefinition

Additional properties of the profile, for example mechanical properties.

IfcParameterizedProfileDef (1)
3 Position OPTIONAL IfcAxis2Placement2D

Position coordinate system of the parameterized profile definition. If unspecified, no translation and no rotation is applied.

Click to show 5 hidden inherited attributes Click to hide 5 inherited attributes
IfcIShapeProfileDef (7)
4 OverallWidth IfcPositiveLengthMeasure

Total extent of the width, defined parallel to the x axis of the position coordinate system.

5 OverallDepth IfcPositiveLengthMeasure

Total extent of the depth, defined parallel to the y axis of the position coordinate system.

6 WebThickness IfcPositiveLengthMeasure

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.

7 FlangeThickness IfcPositiveLengthMeasure

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.

8 FilletRadius OPTIONAL IfcNonNegativeLengthMeasure

The fillet between the web and the flange. 0 if sharp-edged, omitted if unknown.

9 FlangeEdgeRadius OPTIONAL IfcNonNegativeLengthMeasure

Radius of the lower edges of the top flange and the upper edges of the bottom flange. 0 if sharp-edged, omitted if unknown.

10 FlangeSlope OPTIONAL IfcPlaneAngleMeasure

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.

Table 8.15.3.12.C

8.15.3.12.4 Formal propositions

Name Description
ValidFilletRadius

The FilletRadius, if given, shall be within the range of allowed values.

NOT(EXISTS(FilletRadius)) OR
((FilletRadius <= (OverallWidth - WebThickness)/2.) AND 
 (FilletRadius <= (OverallDepth - (2. * FlangeThickness))/2.))
ValidFlangeThickness

The sum of flange thicknesses shall be less than the overall depth.

(2. * FlangeThickness) < OverallDepth
ValidWebThickness

The web thickness shall be less then the flange width.

WebThickness < OverallWidth
Table 8.15.3.12.D

8.15.3.12.5 Property sets

  • Pset_ProfileMechanical
    • MassPerLength
    • CrossSectionArea
    • Perimeter
    • MinimumPlateThickness
    • MaximumPlateThickness
    • CentreOfGravityInX
    • CentreOfGravityInY
    • ShearCentreZ
    • ShearCentreY
    • MomentOfInertiaY
    • MomentOfInertiaZ
    • MomentOfInertiaYZ
    • TorsionalConstantX
    • WarpingConstant
    • ShearDeformationAreaZ
    • ShearDeformationAreaY
    • MaximumSectionModulusY
    • MinimumSectionModulusY
    • MaximumSectionModulusZ
    • MinimumSectionModulusZ
    • TorsionalSectionModulus
    • ShearAreaZ
    • ShearAreaY
    • PlasticShapeFactorY
    • PlasticShapeFactorZ

8.15.3.12.6 Concept usage

Concept Usage Description
IfcProfileDef (1)
Property Sets for Profiles General

This concept can be applied to the following resources:

Click to show 1 hidden inherited concepts Click to hide 1 inherited concepts
Table 8.15.3.12.E

8.15.3.12.7 Formal representation

ENTITY IfcIShapeProfileDef
 SUBTYPE OF (IfcParameterizedProfileDef);
	OverallWidth : IfcPositiveLengthMeasure;
	OverallDepth : IfcPositiveLengthMeasure;
	WebThickness : IfcPositiveLengthMeasure;
	FlangeThickness : IfcPositiveLengthMeasure;
	FilletRadius : OPTIONAL IfcNonNegativeLengthMeasure;
	FlangeEdgeRadius : OPTIONAL IfcNonNegativeLengthMeasure;
	FlangeSlope : OPTIONAL IfcPlaneAngleMeasure;
 WHERE
	ValidFilletRadius : NOT(EXISTS(FilletRadius)) OR
((FilletRadius <= (OverallWidth - WebThickness)/2.) AND 
 (FilletRadius <= (OverallDepth - (2. * FlangeThickness))/2.));
	ValidFlangeThickness : (2. * FlangeThickness) < OverallDepth;
	ValidWebThickness : WebThickness < OverallWidth;
END_ENTITY;

8.15.3.12.8 References

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8.15.3.12.9 Changelog

  • attribute, FlangeEdgeRadius
  • attribute, FlangeSlope
  • where rule, ValidFilletRadius
  • where rule, ValidFlangeThickness
  • where rule, ValidWebThickness
  • where rule, WR1
  • where rule, WR2
  • where rule, WR3
  • attribute FilletRadius type, Changed from "IfcPositiveLengthMeasure" to "IfcNonNegativeLengthMeasure"