IfcAsymmetricIShapeProfileDef

Natural language names
Semantic definitions at the entity
Entity definition

Definition from IAI: The IfcAsymmetricIShapeProfileDef defines a section profile that provides the defining parameters of an asymmetric I-shaped section to be used by the swept area solid. The bottom flange is always wider than the top flange. Its parameters and orientation relative to the position coordinate system are according to the following illustration. The centre of the position coordinate system is in the profiles centre of the gravity bounding box.

The centre of gravity, if given, is located in x direction within the center of the bounding box, and in y-direction along the negative y axis, the offset value is given by the offset parameter CentreOfGravityInY.

NOTE: The inherited attributes are used to define:
  • OverallWidth -- BottomFlangeWidth
  • FlangeThickness -- BottomFlangeThickness
  • FilletRadius -- BottomFlangeFilletRadius.
HISTORY  New entity in Release IFC2x Edition 2.

IFC2x Edition 3 CHANGE  All profile origins are now in the center of the bounding box. The attribute CentreOfGravityInY has been made OPTIONAL. Upward compatibility for file based exchange is guaranteed.

Illustration:

asymmetric I shape profile

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.

Table: Parameters of asymmetric I-shaped section definition

Attribute definitions
#AttributeTypeCardinalityDescription A
9TopFlangeWidthIfcPositiveLengthMeasure[1:1] Extent of the top flange, defined parallel to the x axis of the position coordinate system.X
10TopFlangeThickness- This attribute is out of scope for this model view definition and shall not be set.
11TopFlangeFilletRadius- This attribute is out of scope for this model view definition and shall not be set.
12CentreOfGravityInY- This attribute is out of scope for this model view definition and shall not be set.
Inherited definitions from supertypes
Entity inheritance IfcIShapeProfileDef IfcParameterizedProfileDef IfcProfileDef
Attribute inheritance
#AttributeTypeCardinalityDescriptionA
IfcProfileDef
1ProfileTypeIfcProfileTypeEnum[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
2ProfileName- This attribute is out of scope for this model view definition and shall not be set.
IfcParameterizedProfileDef
3PositionIfcAxis2Placement2D[1:1] Position coordinate system of the parameterized profile definition.X
IfcIShapeProfileDef
4OverallWidthIfcPositiveLengthMeasure[1:1] Total extent of the width, defined parallel to the x axis of the position coordinate system.X
5OverallDepthIfcPositiveLengthMeasure[1:1] Total extent of the depth, defined parallel to the y axis of the position coordinate system.X
6WebThicknessIfcPositiveLengthMeasure[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
7FlangeThicknessIfcPositiveLengthMeasure[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
8FilletRadius- This attribute is out of scope for this model view definition and shall not be set.
IfcAsymmetricIShapeProfileDef
9TopFlangeWidthIfcPositiveLengthMeasure[1:1] Extent of the top flange, defined parallel to the x axis of the position coordinate system.X
10TopFlangeThickness- This attribute is out of scope for this model view definition and shall not be set.
11TopFlangeFilletRadius- This attribute is out of scope for this model view definition and shall not be set.
12CentreOfGravityInY- This attribute is out of scope for this model view definition and shall not be set.
Formal representations
XSD Specification
 <xs:element name="IfcAsymmetricIShapeProfileDef" type="ifc:IfcAsymmetricIShapeProfileDef" substitutionGroup="ifc:IfcIShapeProfileDef" nillable="true"/>
 <xs:complexType name="IfcAsymmetricIShapeProfileDef">
  <xs:complexContent>
   <xs:extension base="ifc:IfcIShapeProfileDef">
    <xs:attribute name="TopFlangeWidth" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcAsymmetricIShapeProfileDef
 SUBTYPE OF (IfcIShapeProfileDef);
  TopFlangeWidth : IfcPositiveLengthMeasure;
  TopFlangeThickness : OPTIONAL IfcStrippedOptional;
  TopFlangeFilletRadius : OPTIONAL IfcStrippedOptional;
  CentreOfGravityInY : OPTIONAL IfcStrippedOptional;
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

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