IfcLShapeProfileDef

Item	SPF	Change	Description
IFC2x3 to IFC4
IfcLShapeProfileDef
Position		MODIFIED	Instantiation changed to OPTIONAL.
FilletRadius		MODIFIED	Type changed from IfcPositiveLengthMeasure to IfcNonNegativeLengthMeasure.
EdgeRadius		MODIFIED	Type changed from IfcPositiveLengthMeasure to IfcNonNegativeLengthMeasure.
CentreOfGravityInX	X	DELETED
CentreOfGravityInY	X	DELETED

Semantic definitions at the entity

Entity definition

IfcLShapeProfileDef defines a section profile that provides the defining parameters of an L-shaped section (equilateral L profiles are also covered by this entity) to be used by the swept area solid. Its parameters and orientation relative to the position coordinate system are according to the following illustration. The shorter leg has the same direction as the positive Position.P[1]-axis, the longer or equal leg the same as the positive Position.P[2]-axis. The centre of the position coordinate system is in the profiles centre of the bounding box.

HISTORY New entity in IFC2x2.

IFC2x3 CHANGE All profile origins are now in the center of the bounding box.

IFC4 CHANGE Types of FilletRadius and EdgeRadius were relaxed to allow for zero values.
Trailing attributes CentreOfGravityInX and CentreOfGravityInY deleted, use respective properties in IfcExtendedProfileProperties instead.
WHERE rule which required Width <= Depth removed.

Figure 420 illustrates parameters of equal-sided and non-equal sided L-shaped section definitions.

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.

In the illustrated example, the 'CentreOfGravityInX' and 'CentreOfGravityInY' properties in IfcExtendedProfileProperties, if provided, are both negative.

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 gravity) the attribute values of IfcAxis2Placement2D are:

Location = IfcCartesianPoint( +|CentreOfGravityInX|, +|CentreOfGravityInY|) RefDirection = NIL (defaults to 1.,0.)

In the illustrated example, the x and y value of Position.Location, i.e. the measures |CentreOfGravityInX| and |CentreOfGravityInY| are both positive. On the other hand, the properties named 'CentreOfGravityInX' and 'CentreOfGravityInY' in IfcExtendedProfileProperties, if provided, must both be set to 0 now because the centre of gravity of the resulting profile definition is located in the coordinate origin.

Figure 420 — L-shape profile

Attribute definitions

#	Attribute	Type	Cardinality	Description	G
4	Depth	IfcPositiveLengthMeasure		Leg length, see illustration above (= h). Same as the overall depth.	X
5	Width	IfcPositiveLengthMeasure	?	Leg length, see illustration above (= b). Same as the overall width. This attribute is formally optional for historic reasons only. Whenever the width is known, it shall be provided by value.	X
6	Thickness	IfcPositiveLengthMeasure		Constant wall thickness of profile, see illustration above (= ts).	X
7	FilletRadius	IfcNonNegativeLengthMeasure	?	Fillet radius according the above illustration (= r1).	X
8	EdgeRadius	IfcNonNegativeLengthMeasure	?	Edge radius according the above illustration (= r2).	X
9	LegSlope	IfcPlaneAngleMeasure	?	Slope of the inner face of each leg of the profile.	X

Formal Propositions

Rule	Description
ValidThickness	The thickness shall be smaller than the depth and width.

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	G
IfcProfileDef
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.	X
2	ProfileName	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.	X
	HasExternalReference	IfcExternalReferenceRelationship @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
	HasProperties	IfcProfileProperties @ProfileDefinition	S[0:?]	Additional properties of the profile, for example mechanical properties. IFC4 CHANGE New inverse attribute	X
IfcParameterizedProfileDef
3	Position	IfcAxis2Placement2D	?	Position coordinate system of the parameterized profile definition. If unspecified, no translation and no rotation is applied.	X
IfcLShapeProfileDef
4	Depth	IfcPositiveLengthMeasure		Leg length, see illustration above (= h). Same as the overall depth.	X
5	Width	IfcPositiveLengthMeasure	?	Leg length, see illustration above (= b). Same as the overall width. This attribute is formally optional for historic reasons only. Whenever the width is known, it shall be provided by value.	X
6	Thickness	IfcPositiveLengthMeasure		Constant wall thickness of profile, see illustration above (= ts).	X
7	FilletRadius	IfcNonNegativeLengthMeasure	?	Fillet radius according the above illustration (= r1).	X
8	EdgeRadius	IfcNonNegativeLengthMeasure	?	Edge radius according the above illustration (= r2).	X
9	LegSlope	IfcPlaneAngleMeasure	?	Slope of the inner face of each leg of the profile.	X

#	Concept	Template	Model View
IfcProfileDef
	Property Sets for Objects	Property Sets for Objects	General Usage

Formal representations

XML Specification

 <xs:element name="IfcLShapeProfileDef" type="ifc:IfcLShapeProfileDef" substitutionGroup="ifc:IfcParameterizedProfileDef" nillable="true"/>

 <xs:complexType name="IfcLShapeProfileDef">

  <xs:complexContent>

   <xs:extension base="ifc:IfcParameterizedProfileDef">

    <xs:attribute name="Depth" type="ifc:IfcPositiveLengthMeasure" use="optional"/>

    <xs:attribute name="Width" type="ifc:IfcPositiveLengthMeasure" use="optional"/>

    <xs:attribute name="Thickness" type="ifc:IfcPositiveLengthMeasure" use="optional"/>

    <xs:attribute name="FilletRadius" type="ifc:IfcNonNegativeLengthMeasure" use="optional"/>

    <xs:attribute name="EdgeRadius" type="ifc:IfcNonNegativeLengthMeasure" use="optional"/>

    <xs:attribute name="LegSlope" type="ifc:IfcPlaneAngleMeasure" use="optional"/>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcLShapeProfileDef

 SUBTYPE OF (IfcParameterizedProfileDef);

  Depth : IfcPositiveLengthMeasure;

  Width : OPTIONAL IfcPositiveLengthMeasure;

  Thickness : IfcPositiveLengthMeasure;

  FilletRadius : OPTIONAL IfcNonNegativeLengthMeasure;

  EdgeRadius : OPTIONAL IfcNonNegativeLengthMeasure;

  LegSlope : OPTIONAL IfcPlaneAngleMeasure;

 WHERE

  ValidThickness : (Thickness < Depth) AND (NOT(EXISTS(Width)) OR (Thickness < Width));
END_ENTITY;

 EXPRESS-G diagram

	L-Profil - parametrische Definition
	LShape Profile Def
	Définition de section d'un profil en L

IfcLShapeProfileDef

Semantic definitions at the entity

Inherited definitions from supertypes

Definitions applying to General Usage

Formal representations