IFC (IFC4X3_ADD2) under development IfcOpenCrossProfileDef Semantic definition

A two-dimensional open profile defined by widths and slopes for the use within the swept surface geometry, in SectionedSurface in particular. The underlying coordinate system is defined by the swept surface that uses the profile definition; when used in SectionedSurface it is the XY plane of each list member of SectionedSurface.CrossSectionPositions where the profile X axis is oriented perpendicularly to the left of the Directrix (same direction as positive LateralOffset at IfcPointByDistanceExpression) as facing forward along the directrix, and the profile Y axis is oriented upwards or vertically perpendicular to the Directrix depending on the usage in the SectionedSurface.

The behaviour of OpenCrossProfileDef in sweeping operation can be controlled by attribute Tags. Tags allow two consecutive cross sections to have different number of break points: points with the same tag value are connected either by assuming linear longitudinal breakline between them, or by a guide curve identified by the same Tag value as the cross section points.

open cross profile
Figure — Open cross profile Entity inheritance 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.

Click to show 4 hidden inherited attributes Click to hide 4 inherited attributes
IfcOpenCrossProfileDef (5)
3 HorizontalWidths IfcBoolean

Indicates if the widths shall be measured horizontally or along the slopes.

4 Widths LIST [1:?] OF IfcNonNegativeLengthMeasure

The horizontal widths (when HorizontalWidths=.T.) or distances along the Slope (when HorizontalWidths=.F.) for the segments in the profile. And if Horizontal=.T. the Slopes shall not be = +/- 90 deg.

5 Slopes LIST [1:?] OF IfcPlaneAngleMeasure

The slope measure.

6 Tags OPTIONAL LIST [2:?] OF IfcLabel

No description available.

7 OffsetPoint OPTIONAL IfcCartesianPoint

Optional Cartesian point to nominate the profile curve start. The provided slopes and widths emerge from this point. If no value is given, the profile initiates at the alignment intersection with the profile plane.

Table Formal propositions

Name Description

The profile type shall be CURVE.

SELF\IfcProfileDef.ProfileType = IfcProfileTypeEnum.CURVE

The list of slopes and the list of widths shall be of the same size.

SIZEOF(Slopes) = SIZEOF(Widths)

The list of tags shall have one more member.

(NOT EXISTS (Tags)) OR (SIZEOF(Tags) = (SIZEOF(Slopes) + 1))
Table 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 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 Formal representation

ENTITY IfcOpenCrossProfileDef
 SUBTYPE OF (IfcProfileDef);
	HorizontalWidths : IfcBoolean;
	Widths : LIST [1:?] OF IfcNonNegativeLengthMeasure;
	Slopes : LIST [1:?] OF IfcPlaneAngleMeasure;
	Tags : OPTIONAL LIST [2:?] OF IfcLabel;
	OffsetPoint : OPTIONAL IfcCartesianPoint;
	CorrectProfileType : SELF\IfcProfileDef.ProfileType = IfcProfileTypeEnum.CURVE;
	CorrespondingSlopeWidths : SIZEOF(Slopes) = SIZEOF(Widths);
	CorrespondingTags : (NOT EXISTS (Tags)) OR (SIZEOF(Tags) = (SIZEOF(Slopes) + 1));
END_ENTITY; References

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