IfcLShapeProfileDef

Natural language names
L-Profil - parametrische Definition
LShape Profile Def
Définition de section d'un profil en L
Change log
ItemSPFXMLChangeDescription
IFC2x3 to IFC4
    IfcLShapeProfileDef
      PositionMODIFIEDInstantiation changed to OPTIONAL.
      FilletRadiusMODIFIEDType changed from IfcPositiveLengthMeasure to IfcNonNegativeLengthMeasure.
      EdgeRadiusMODIFIEDType changed from IfcPositiveLengthMeasure to IfcNonNegativeLengthMeasure.
      CentreOfGravityInXXDELETED
      CentreOfGravityInYXDELETED
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 423 illustrates parameters of equal-sided and non-equal sided L-shaped section definitions.

non equal sided L-shape

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.

equal sided L-shape
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 423 — L-shape profile

Attribute definitions
#AttributeTypeCardinalityDescription G
4DepthIfcPositiveLengthMeasure Leg length, see illustration above (= h). Same as the overall depth.X
5WidthIfcPositiveLengthMeasure? 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
6ThicknessIfcPositiveLengthMeasure Constant wall thickness of profile, see illustration above (= ts).X
7FilletRadiusIfcNonNegativeLengthMeasure? Fillet radius according the above illustration (= r1).X
8EdgeRadiusIfcNonNegativeLengthMeasure? Edge radius according the above illustration (= r2).X
9LegSlopeIfcPlaneAngleMeasure? Slope of the inner face of each leg of the profile.X
Formal Propositions
RuleDescription
ValidThicknessThe thickness shall be smaller than the depth and width.
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
IfcLShapeProfileDef
4DepthIfcPositiveLengthMeasure Leg length, see illustration above (= h). Same as the overall depth.X
5WidthIfcPositiveLengthMeasure? 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
6ThicknessIfcPositiveLengthMeasure Constant wall thickness of profile, see illustration above (= ts).X
7FilletRadiusIfcNonNegativeLengthMeasure? Fillet radius according the above illustration (= r1).X
8EdgeRadiusIfcNonNegativeLengthMeasure? Edge radius according the above illustration (= r2).X
9LegSlopeIfcPlaneAngleMeasure? Slope of the inner face of each leg of the profile.X
Definitions applying to General Usage

Concept inheritance

#ConceptTemplateModel View
IfcProfileDef
Property Sets for ObjectsProperty Sets for ObjectsGeneral 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;

Link to EXPRESS-G diagram EXPRESS-G diagram

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